diff --git a/cabal.project b/cabal.project
index 54a9bd05ca1..cf33598d748 100644
--- a/cabal.project
+++ b/cabal.project
@@ -15,10 +15,10 @@ repository cardano-haskell-packages
 -- repeat the index-state for hackage to work around haskell.nix parsing limitation
 index-state:
   -- Bump this if you need newer packages from Hackage
-  , hackage.haskell.org 2026-03-04T10:56:45Z
+  , hackage.haskell.org 2026-05-13T07:31:22Z
 
   -- Bump this if you need newer packages from CHaP
-  , cardano-haskell-packages 2026-03-30T15:30:34Z
+  , cardano-haskell-packages 2026-05-11T20:15:43Z
 
 active-repositories:
   , :rest
@@ -32,6 +32,14 @@ packages: ./cardano-ping
           ./ntp-client
           ./acts-generic
 
+-- TODO: contra-tracer 0.2.1.0 is on Hackage but shadowed by CHaP's 0.1.x under
+-- active-repositories: cardano-haskell-packages:override.
+source-repository-package
+  type: git
+  location: https://github.com/avieth/contra-tracer
+  tag: bf4a562a3b1315946aca7f6b4935e94ca1a23aa9
+  --sha256: 1d3zlyi8hlmwhfa2dw3icprr6rgx1xnfds5vk1rmchpjcvmz6bkb
+
 tests: True
 benchmarks: True
 
diff --git a/cardano-diffusion/cardano-diffusion.cabal b/cardano-diffusion/cardano-diffusion.cabal
index 178e77d8279..b59be7469ab 100644
--- a/cardano-diffusion/cardano-diffusion.cabal
+++ b/cardano-diffusion/cardano-diffusion.cabal
@@ -96,7 +96,7 @@ library api-tests-lib
     Cardano.Network.NodeToNode.Version.TestUtils
 
   build-depends:
-    QuickCheck,
+    QuickCheck < 2.18,
     base >=4.14 && <4.23,
     cardano-diffusion:api,
     ouroboros-network:api,
@@ -112,7 +112,7 @@ test-suite api-tests
     Test.Cardano.Network.Version
 
   build-depends:
-    QuickCheck,
+    QuickCheck < 2.18,
     base >=4.14 && <4.23,
     cardano-diffusion:{api, api-tests-lib},
     ouroboros-network:api,
@@ -371,7 +371,7 @@ library protocols-tests-lib
     Ouroboros.Network.Protocol.TxSubmission2.Test as Cardano.Network.Protocol.TxSubmission2.Test,
 
   build-depends:
-    QuickCheck,
+    QuickCheck < 2.18,
     base >=4.14 && <4.23,
     bytestring,
     cardano-diffusion:{api, api-tests-lib, protocols},
@@ -416,7 +416,7 @@ test-suite protocols-cddl
     buildable: False
 
   build-depends:
-    QuickCheck,
+    QuickCheck < 2.18,
     base >=4.14 && <4.23,
     bytestring,
     cardano-diffusion:{api, api-tests-lib, protocols, protocols-tests-lib},
@@ -479,7 +479,7 @@ library cardano-diffusion-tests-lib
   visibility: public
   hs-source-dirs: tests/lib
   build-depends:
-    QuickCheck,
+    QuickCheck < 2.18,
     aeson,
     base >=4.14 && <4.23,
     bytestring,
@@ -559,7 +559,7 @@ library subscription
     cardano-diffusion ^>=1.0.0.0,
     cborg >=0.2.8 && <0.3,
     containers >=0.5 && <0.9,
-    contra-tracer >=0.1 && <0.3,
+    contra-tracer ^>=0.2.1,
     deepseq,
     io-classes:si-timers ^>=1.8.0.1,
     network-mux ^>=0.10.1.0,
diff --git a/cardano-diffusion/changelog.d/20260513_170556_fabrizio.ferrai_contra_tracer_0_2_1.md b/cardano-diffusion/changelog.d/20260513_170556_fabrizio.ferrai_contra_tracer_0_2_1.md
new file mode 100644
index 00000000000..6658a989751
--- /dev/null
+++ b/cardano-diffusion/changelog.d/20260513_170556_fabrizio.ferrai_contra_tracer_0_2_1.md
@@ -0,0 +1,5 @@
+### Breaking
+
+- Upgraded to `contra-tracer ^>=0.2.1`. The `Tracer` data constructor is no
+  longer exported; use `mkTracer` instead.
+- Capped `QuickCheck < 2.18`.
diff --git a/cardano-diffusion/tests/lib/Test/Cardano/Network/Diffusion/Testnet/Simulation.hs b/cardano-diffusion/tests/lib/Test/Cardano/Network/Diffusion/Testnet/Simulation.hs
index 97707c66b07..45442f30f6a 100644
--- a/cardano-diffusion/tests/lib/Test/Cardano/Network/Diffusion/Testnet/Simulation.hs
+++ b/cardano-diffusion/tests/lib/Test/Cardano/Network/Diffusion/Testnet/Simulation.hs
@@ -52,7 +52,7 @@ import Control.Monad.Class.MonadTime.SI
 import Control.Monad.Class.MonadTimer.SI
 import Control.Monad.Fix
 import Control.Monad.IOSim (IOSim)
-import Control.Tracer (Tracer (..), contramap, nullTracer, traceWith)
+import Control.Tracer (Tracer, contramap, mkTracer, nullTracer, traceWith)
 
 import Data.Bifunctor (first)
 import Data.Bool (bool)
@@ -1330,7 +1330,7 @@ diffusionSimulationM
               , Node.aTimeWaitTimeout      = 30
               , Node.aDNSTimeoutScript     = dnsTimeout
               , Node.aDNSLookupDelayScript = dnsLookupDelay
-              , Node.aDebugTracer          = Tracer (\s -> do
+              , Node.aDebugTracer          = mkTracer (\s -> do
                                               t <- getMonotonicTime
                                               traceWith nodeTracer $ WithTime t (WithName addr (DiffusionDebugTrace s)))
               , Node.aExtraChurnArgs       = cardanoChurnArgs
@@ -1480,7 +1480,7 @@ diffusionSimulationM
                            m
     mkTracers ntnAddr nodeId =
       let sayTracer' :: Show event => Tracer m event
-          sayTracer' = Tracer $ \event ->
+          sayTracer' = mkTracer $ \event ->
                        -- time of events is added in `testWithIOSim` and
                        -- `testWithIOSimPOR`
                        say $ show nodeId ++ " @ " ++ show event
diff --git a/cardano-diffusion/tests/lib/Test/Cardano/Network/PeerSelection.hs b/cardano-diffusion/tests/lib/Test/Cardano/Network/PeerSelection.hs
index 428f0ab147a..423e393d5af 100644
--- a/cardano-diffusion/tests/lib/Test/Cardano/Network/PeerSelection.hs
+++ b/cardano-diffusion/tests/lib/Test/Cardano/Network/PeerSelection.hs
@@ -32,7 +32,7 @@ import Control.Exception (AssertionFailed (..), catch, evaluate)
 import Control.Monad (when)
 import Control.Monad.Class.MonadTime.SI
 import Control.Monad.Class.MonadTimer.SI
-import Control.Tracer (Tracer (..))
+import Control.Tracer (Tracer, mkTracer)
 
 import Data.Bifoldable (bitraverse_)
 import Data.ByteString.Char8 qualified as BS
@@ -4289,7 +4289,7 @@ _governorFindingPublicRoots targetNumberOfRootPeers readDomains readUseBootstrap
     tracer' = tracer
 
     tracer :: Show a => Tracer IO a
-    tracer  = Tracer (BS.putStrLn . BS.pack . show)
+    tracer  = mkTracer (BS.putStrLn . BS.pack . show)
 
     actions
       :: PeerSelectionActions
diff --git a/cardano-diffusion/tests/lib/Test/Cardano/Network/PeerSelection/MockEnvironment.hs b/cardano-diffusion/tests/lib/Test/Cardano/Network/PeerSelection/MockEnvironment.hs
index 8092093b9c9..d1a93b705d5 100644
--- a/cardano-diffusion/tests/lib/Test/Cardano/Network/PeerSelection/MockEnvironment.hs
+++ b/cardano-diffusion/tests/lib/Test/Cardano/Network/PeerSelection/MockEnvironment.hs
@@ -60,7 +60,7 @@ import Control.Monad.Class.MonadTime.SI
 import Control.Monad.Class.MonadTimer.SI hiding (timeout)
 import Control.Monad.Fail qualified as Fail
 import Control.Monad.IOSim
-import Control.Tracer (Tracer (..), contramap, traceWith)
+import Control.Tracer (Tracer, contramap, mkTracer, traceWith)
 
 import Ouroboros.Network.BlockFetch (FetchMode (..), PraosFetchMode (..))
 import Ouroboros.Network.ConnectionManager.Types (Provenance)
@@ -838,7 +838,7 @@ traceAssociationMode
 
   -> Tracer (IOSim s)
            (DebugPeerSelection Cardano.ExtraState extraFlags extraPeers PeerAddr)
-traceAssociationMode interfaces actions = Tracer $ \(TraceGovernorState _ _ st) -> do
+traceAssociationMode interfaces actions = mkTracer $ \(TraceGovernorState _ _ st) -> do
     associationMode <- atomically $ readAssociationMode
                                            (readUseLedgerPeers interfaces)
                                            (Governor.peerSharing actions)
diff --git a/cardano-ping/cardano-ping.cabal b/cardano-ping/cardano-ping.cabal
index 25e7084229e..a291a4a7484 100644
--- a/cardano-ping/cardano-ping.cabal
+++ b/cardano-ping/cardano-ping.cabal
@@ -30,7 +30,7 @@ library
     base >=4.14 && <4.23,
     bytestring >=0.10 && <0.13,
     cborg >=0.2.8 && <0.3,
-    contra-tracer >=0.1 && <0.3,
+    contra-tracer ^>=0.2.1,
     io-classes:{si-timers, strict-stm} ^>=1.8,
     iproute ^>=1.7.15,
     network ^>=3.2.7,
diff --git a/cardano-ping/changelog.d/20260513_170556_fabrizio.ferrai_contra_tracer_0_2_1.md b/cardano-ping/changelog.d/20260513_170556_fabrizio.ferrai_contra_tracer_0_2_1.md
new file mode 100644
index 00000000000..35bbc00813d
--- /dev/null
+++ b/cardano-ping/changelog.d/20260513_170556_fabrizio.ferrai_contra_tracer_0_2_1.md
@@ -0,0 +1,4 @@
+### Breaking
+
+- Upgraded to `contra-tracer ^>=0.2.1`. The `Tracer` data constructor is no
+  longer exported; use `mkTracer` instead.
diff --git a/flake.lock b/flake.lock
index 219805816a6..8b710e7cccf 100644
--- a/flake.lock
+++ b/flake.lock
@@ -3,11 +3,11 @@
     "CHaP": {
       "flake": false,
       "locked": {
-        "lastModified": 1774886932,
-        "narHash": "sha256-onVCoKUFr0Fbl49jq8L9quipNrdabrcEQVd3oWCq+PY=",
+        "lastModified": 1778700436,
+        "narHash": "sha256-6KW3OSVTA7yBvOEgFXmQrquSwN9wX3r5Hfk3mgnUfso=",
         "owner": "intersectmbo",
         "repo": "cardano-haskell-packages",
-        "rev": "d7555a1b7297f1d0c67b4ea28b6dae7eb08c2366",
+        "rev": "2d77199bbdf795a52169bbcf8eae88aee3794bad",
         "type": "github"
       },
       "original": {
@@ -189,11 +189,11 @@
     "hackageNix": {
       "flake": false,
       "locked": {
-        "lastModified": 1772789029,
-        "narHash": "sha256-mkVaepN/M9ikvw2HD/PAaOOhT3dR02BlpbFdtn4gM6c=",
+        "lastModified": 1778699418,
+        "narHash": "sha256-0RBSLTlZ7XSw3uSePPzdVcgN/d+h54pQf3BYFRXQSz0=",
         "owner": "input-output-hk",
         "repo": "hackage.nix",
-        "rev": "7ca657c7cf313ccfaf3f131c53121b44f8b852cf",
+        "rev": "37678bd46977723db19f5d97ae6e8cd6847e9cbf",
         "type": "github"
       },
       "original": {
diff --git a/network-mux/changelog.d/20260513_170556_fabrizio.ferrai_contra_tracer_0_2_1.md b/network-mux/changelog.d/20260513_170556_fabrizio.ferrai_contra_tracer_0_2_1.md
new file mode 100644
index 00000000000..88c067480e8
--- /dev/null
+++ b/network-mux/changelog.d/20260513_170556_fabrizio.ferrai_contra_tracer_0_2_1.md
@@ -0,0 +1,7 @@
+### Breaking
+
+- Upgraded to `contra-tracer ^>=0.2.1`. The `Tracer` data constructor is no
+  longer exported; use `mkTracer` instead. `nullTracers`, the `TracersI`
+  pattern synonym, `contramapTracers'`, `tracersWithBearer` and
+  `traceBearerState` now require `Monad m` rather than `Applicative m`.
+- Capped `QuickCheck < 2.18`.
diff --git a/network-mux/demo/mux-demo.hs b/network-mux/demo/mux-demo.hs
index ab63ce3bf60..60e590db5f9 100644
--- a/network-mux/demo/mux-demo.hs
+++ b/network-mux/demo/mux-demo.hs
@@ -19,7 +19,7 @@ import Control.Concurrent (forkIO)
 import Control.Concurrent.STM (atomically)
 import Control.Exception (finally)
 import Control.Monad
-import Control.Tracer (Tracer (..))
+import Control.Tracer (Tracer, mkTracer)
 
 import System.Environment qualified as SysEnv
 import System.Exit
@@ -72,7 +72,7 @@ putStrLn_ :: String -> IO ()
 putStrLn_ = BSC.putStrLn . BSC.pack
 
 debugTracer :: Show a => Tracer IO a
-debugTracer = show >$< Tracer putStrLn_
+debugTracer = show >$< mkTracer putStrLn_
 
 --
 -- Protocols
diff --git a/network-mux/demo/mux-leios-demo.hs b/network-mux/demo/mux-leios-demo.hs
index 8dd7ca05677..44c47eee740 100644
--- a/network-mux/demo/mux-leios-demo.hs
+++ b/network-mux/demo/mux-leios-demo.hs
@@ -98,7 +98,7 @@ reqrespTracer
   :: String
   -- ^ tag
   -> Tracer IO (TraceSendRecv (MsgReqResp ByteString ByteString))
-reqrespTracer tag = Tracer $ \case
+reqrespTracer tag = mkTracer $ \case
   TraceSend (MsgReq a)  -> putStrLn_ $ tag ++ " Send MsgReq " ++ show (BSC.length a)
   TraceSend (MsgResp a) -> putStrLn_ $ tag ++ " Send MsgResp " ++ show (BSC.length a)
   TraceSend MsgDone     -> putStrLn_ $ tag ++ " Send MsgDone"
diff --git a/network-mux/network-mux.cabal b/network-mux/network-mux.cabal
index 76b152d0e0f..b26cfd1acf5 100644
--- a/network-mux/network-mux.cabal
+++ b/network-mux/network-mux.cabal
@@ -58,7 +58,7 @@ library
     binary >=0.8 && <0.11,
     bytestring >=0.10 && <0.13,
     containers >=0.5 && <0.9,
-    contra-tracer >=0.1 && <0.2,
+    contra-tracer ^>=0.2.1,
     io-classes:{io-classes, si-timers, strict-stm} ^>=1.8,
     monoidal-synchronisation >=0.1 && <0.2,
     network ^>=3.2.7,
@@ -135,7 +135,7 @@ test-suite test
   default-language: Haskell2010
   default-extensions: ImportQualifiedPost
   build-depends:
-    QuickCheck,
+    QuickCheck < 2.18,
     Win32-network,
     base >=4.14 && <4.23,
     binary,
diff --git a/network-mux/src/Network/Mux.hs b/network-mux/src/Network/Mux.hs
index 8df0b266f50..c1d25172a9a 100644
--- a/network-mux/src/Network/Mux.hs
+++ b/network-mux/src/Network/Mux.hs
@@ -723,7 +723,7 @@ muxChannel tracer egressQueue want@(Wanton w) mc md q =
         traceWith tracer $ TraceChannelRecvEnd mc (fromIntegral $ BL.length blob)
         return $ Just blob
 
-traceBearerState :: Tracer m Trace -> State -> m ()
+traceBearerState :: Monad m => Tracer m Trace -> State -> m ()
 traceBearerState tracer state =
     traceWith tracer (TraceState state)
 
diff --git a/network-mux/src/Network/Mux/DeltaQ/TraceTransformer.hs b/network-mux/src/Network/Mux/DeltaQ/TraceTransformer.hs
index 318402a174b..9802c1adf6e 100644
--- a/network-mux/src/Network/Mux/DeltaQ/TraceTransformer.hs
+++ b/network-mux/src/Network/Mux/DeltaQ/TraceTransformer.hs
@@ -9,7 +9,6 @@ module Network.Mux.DeltaQ.TraceTransformer
 
 import Control.Concurrent.Class.MonadSTM.Strict
 import Control.Tracer
-import Data.Functor.Contravariant ((>$<))
 import Data.Functor.Identity
 
 import Network.Mux.DeltaQ.TraceStats
@@ -35,7 +34,7 @@ dqTracer :: MonadSTM m
          => StrictTVar m StatsA
          -> Tracer m BearerTrace
          -> Tracer m BearerTrace
-dqTracer sTvar tr = Tracer go
+dqTracer sTvar tr = mkTracer go
   where
     go (TraceRecvDeltaQObservation SDUHeader { mhTimestamp, mhLength } t)
       = update mhTimestamp t (fromIntegral mhLength)
diff --git a/network-mux/src/Network/Mux/Trace.hs b/network-mux/src/Network/Mux/Trace.hs
index b1449e4664b..be955e24c39 100644
--- a/network-mux/src/Network/Mux/Trace.hs
+++ b/network-mux/src/Network/Mux/Trace.hs
@@ -209,7 +209,7 @@ tracersWith tr = Tracers {
   }
 
 
-nullTracers :: Applicative m => Tracers' m f
+nullTracers :: Monad m => Tracers' m f
 nullTracers = tracersWith nullTracer
 
 
@@ -217,6 +217,7 @@ nullTracers = tracersWith nullTracer
 -- functor in the `Tracer` type.
 --
 pattern TracersI :: forall m.
+                    Monad m =>
                     Tracer m Trace
                  -> Tracer m ChannelTrace
                  -> Tracer m BearerTrace
@@ -238,7 +239,8 @@ pattern TracersI { tracer_, channelTracer_, bearerTracer_ } <-
 
 -- | Contravariant natural transformation of `Tracers' m`.
 --
-contramapTracers' :: (forall x. f' x -> f x)
+contramapTracers' :: Monad m
+                  => (forall x. f' x -> f x)
                   -> Tracers' m f -> Tracers' m f'
 contramapTracers'
   f
@@ -255,5 +257,5 @@ contramapTracers'
 
 type TracersWithBearer connId m = Tracers' m (WithBearer connId)
 
-tracersWithBearer :: peerId -> TracersWithBearer peerId m -> Tracers m
+tracersWithBearer :: Monad m => peerId -> TracersWithBearer peerId m -> Tracers m
 tracersWithBearer peerId = contramapTracers' (WithBearer peerId . runIdentity)
diff --git a/network-mux/test/Test/Mux.hs b/network-mux/test/Test/Mux.hs
index 8b7627b4112..4f656fe2c96 100644
--- a/network-mux/test/Test/Mux.hs
+++ b/network-mux/test/Test/Mux.hs
@@ -28,7 +28,6 @@ import Data.Binary.Put qualified as Bin
 import Data.Bits
 import Data.ByteString.Lazy qualified as BL
 import Data.ByteString.Lazy.Char8 qualified as BL8 (pack)
-import Data.Functor.Contravariant ((>$<))
 import Data.List (dropWhileEnd, nub)
 import Data.List qualified as List
 import Data.Map qualified as M
@@ -1009,7 +1008,7 @@ prop_mux_starvation (Uneven response0 response1) =
     activeMpsVar <- newTVarIO 0
     traceHeaderVar <- newTVarIO []
     let headerTracer =
-          Tracer $ \e -> case e of
+          mkTracer $ \e -> case e of
             Mx.TraceRecvHeaderEnd header
               -> atomically (modifyTVar traceHeaderVar (header:))
             _ -> return ()
@@ -1914,7 +1913,7 @@ verboseTracer :: forall a m.
                        , Show a
                        )
                => Tracer m a
-verboseTracer = threadAndTimeTracer $ show >$< Tracer say
+verboseTracer = threadAndTimeTracer $ show >$< mkTracer say
 
 muxVerboseTracer :: forall m.
                        ( MonadAsync m
@@ -1929,7 +1928,7 @@ threadAndTimeTracer :: forall a m.
                        , MonadMonotonicTime m
                        )
                     => Tracer m (WithThreadAndTime a) -> Tracer m a
-threadAndTimeTracer tr = Tracer $ \s -> do
+threadAndTimeTracer tr = mkTracer $ \s -> do
     !now <- getMonotonicTime
     !tid <- myThreadId
     traceWith tr $ WithThreadAndTime now (show tid) s
diff --git a/nix/ouroboros-network.nix b/nix/ouroboros-network.nix
index 7e6f650bad0..9648f3c61f3 100644
--- a/nix/ouroboros-network.nix
+++ b/nix/ouroboros-network.nix
@@ -110,9 +110,6 @@ let
         packages.ouroboros-network.components.tests.framework-sim-tests.doCheck = onLinux;
         packages.ouroboros-network.components.tests.ouroboros-network-sim-tests.doCheck = onLinux;
       })
-      ({ pkgs, ... }: lib.mkIf pkgs.stdenv.hostPlatform.isWindows {
-        packages.basement.configureFlags = [ "--hsc2hs-options=--cflag=-Wno-int-conversion" ];
-      })
     ];
   });
 in
diff --git a/ntp-client/changelog.d/20260513_170556_fabrizio.ferrai_contra_tracer_0_2_1.md b/ntp-client/changelog.d/20260513_170556_fabrizio.ferrai_contra_tracer_0_2_1.md
new file mode 100644
index 00000000000..35bbc00813d
--- /dev/null
+++ b/ntp-client/changelog.d/20260513_170556_fabrizio.ferrai_contra_tracer_0_2_1.md
@@ -0,0 +1,4 @@
+### Breaking
+
+- Upgraded to `contra-tracer ^>=0.2.1`. The `Tracer` data constructor is no
+  longer exported; use `mkTracer` instead.
diff --git a/ntp-client/demo/Main.hs b/ntp-client/demo/Main.hs
index 64717fe880c..2c75635164d 100644
--- a/ntp-client/demo/Main.hs
+++ b/ntp-client/demo/Main.hs
@@ -5,7 +5,6 @@ import Control.Concurrent (threadDelay)
 import Control.Concurrent.Async
 import Control.Monad (forever)
 import Control.Tracer
-import Data.Functor.Contravariant ((>$<))
 
 import Network.NTP.Client (NtpClient (..), NtpSettings (..), withNtpClient)
 
diff --git a/ntp-client/ntp-client.cabal b/ntp-client/ntp-client.cabal
index d5bb20340cf..5dec6c3fcbe 100644
--- a/ntp-client/ntp-client.cabal
+++ b/ntp-client/ntp-client.cabal
@@ -33,7 +33,7 @@ library
     base >=4.14 && <4.23,
     binary >=0.8 && <0.11,
     bytestring >=0.10 && <0.13,
-    contra-tracer >=0.1 && <0.2,
+    contra-tracer ^>=0.2.1,
     network ^>=3.2.7,
     stm >=2.4 && <2.6,
     time >=1.9.1 && <1.16,
@@ -62,7 +62,7 @@ test-suite test
   other-modules: Network.NTP.Client.Packet
   type: exitcode-stdio-1.0
   build-depends:
-    QuickCheck,
+    QuickCheck < 2.18,
     base >=4.14 && <4.23,
     binary >=0.8 && <0.11,
     tasty,
@@ -90,7 +90,7 @@ executable demo-ntp-client
     Win32-network >=0.1 && <0.3,
     async >=2.2 && <2.3,
     base >=4.14 && <4.23,
-    contra-tracer >=0.1 && <0.2,
+    contra-tracer ^>=0.2.1,
     ntp-client,
 
   default-language: Haskell2010
diff --git a/ouroboros-network/changelog.d/20260513_170556_fabrizio.ferrai_contra_tracer_0_2_1.md b/ouroboros-network/changelog.d/20260513_170556_fabrizio.ferrai_contra_tracer_0_2_1.md
new file mode 100644
index 00000000000..3408a951e9c
--- /dev/null
+++ b/ouroboros-network/changelog.d/20260513_170556_fabrizio.ferrai_contra_tracer_0_2_1.md
@@ -0,0 +1,7 @@
+### Breaking
+
+- Upgraded to `contra-tracer ^>=0.2.1`. The `Tracer` data constructor is no
+  longer exported; use `mkTracer` instead. `Diffusion.Types.nullTracers` and
+  `Socket.nullNetworkConnectTracers` now require `Monad m` rather than
+  `Applicative m`.
+- Capped `QuickCheck < 2.18`.
diff --git a/ouroboros-network/demo/connection-manager.hs b/ouroboros-network/demo/connection-manager.hs
index 1ad711fb72c..fb80bd5437c 100644
--- a/ouroboros-network/demo/connection-manager.hs
+++ b/ouroboros-network/demo/connection-manager.hs
@@ -33,7 +33,7 @@ import Control.Monad.Class.MonadThrow
 import Control.Monad.Class.MonadTime.SI (MonadTime (..))
 import Control.Monad.Class.MonadTimer.SI
 import Control.Monad.Fix (MonadFix)
-import Control.Tracer (Tracer (..), contramap, nullTracer, traceWith)
+import Control.Tracer (Tracer, contramap, mkTracer, nullTracer, traceWith)
 
 import Data.ByteString.Lazy (ByteString)
 import Data.Either (partitionEithers)
@@ -727,6 +727,6 @@ forever' io = do
 
 
 debugTracer :: (MonadSay m, MonadTime m, Show a) => Tracer m a
-debugTracer = Tracer $ \msg -> do
+debugTracer = mkTracer $ \msg -> do
     t <- getCurrentTime
     say (show t ++ " " ++ show msg)
diff --git a/ouroboros-network/demo/tx-submission/main.hs b/ouroboros-network/demo/tx-submission/main.hs
index 3422d026e02..dba6cb5233a 100644
--- a/ouroboros-network/demo/tx-submission/main.hs
+++ b/ouroboros-network/demo/tx-submission/main.hs
@@ -29,7 +29,7 @@ import Control.Concurrent.MVar (MVar, newMVar, withMVar)
 import Control.Exception
 import Control.Monad
 import Control.Monad.Class.MonadTimer.SI
-import Control.Tracer (Tracer (..))
+import Control.Tracer (Tracer, mkTracer)
 import Control.Tracer qualified as Tracer
 import Data.ByteString (ByteString)
 import Data.ByteString qualified as BS
@@ -94,7 +94,7 @@ main =
               { V2.maxUnacknowledgedTxIds
               }
         lock <- newMVar ()
-        let stderrTracer = Tracer $ \msg -> withMVar lock $ \_ -> hPutStrLn stderr msg
+        let stderrTracer = mkTracer $ \msg -> withMVar lock $ \_ -> hPutStrLn stderr msg
             addrs :: [Addr]
             addrs = fmap (\a -> bindAddr { port = port bindAddr + fromIntegral a })
                          [0..(num - 1)]
@@ -368,7 +368,7 @@ prettyWithBearer pretty (Mx.WithBearer addr a) =
 
 txSubmissionTracer :: MVar () -> Tracer IO (Mx.WithBearer Socket.SockAddr (Driver.TraceSendRecv TxSubmission))
 txSubmissionTracer lock =
-    Tracer $ \msg ->
+    mkTracer $ \msg ->
       withMVar lock $ \_ -> putStrLn (prettyWithBearer prettyMsg msg)
   where
     prettyMsg :: Driver.TraceSendRecv TxSubmission -> String
@@ -410,7 +410,7 @@ txSubmissionTracer lock =
 
 inboundTracer :: MVar () -> Tracer IO (Mx.WithBearer Socket.SockAddr (V2.TraceTxSubmissionInbound TxId Tx))
 inboundTracer lock =
-    Tracer $ \msg ->
+    mkTracer $ \msg ->
       withMVar lock $ \_ -> putStrLn (prettyWithBearer prettyMsg msg)
   where
     prettyMsg :: V2.TraceTxSubmissionInbound TxId Tx -> String
@@ -435,7 +435,7 @@ inboundTracer lock =
 
 
 printTracer :: Show a => MVar () -> Tracer IO (Mx.WithBearer Socket.SockAddr a)
-printTracer lock = Tracer $ \(Mx.WithBearer addr a) ->
+printTracer lock = mkTracer $ \(Mx.WithBearer addr a) ->
   withMVar lock $ \_ -> putStrLn (show addr ++ " " ++ show a)
 
 
diff --git a/ouroboros-network/framework/io-tests/Test/Ouroboros/Network/Socket.hs b/ouroboros-network/framework/io-tests/Test/Ouroboros/Network/Socket.hs
index 0e7037b4dcc..dba67a8c2ed 100644
--- a/ouroboros-network/framework/io-tests/Test/Ouroboros/Network/Socket.hs
+++ b/ouroboros-network/framework/io-tests/Test/Ouroboros/Network/Socket.hs
@@ -546,10 +546,10 @@ instance (Show a) => Show (WithThreadAndTime a) where
         printf "%s: %s: %s" (show wtatOccuredAt) (show wtatWithinThread) (show wtatEvent)
 
 _verboseTracer :: Show a => Tracer IO a
-_verboseTracer = threadAndTimeTracer $ showTracing stdoutTracer
+_verboseTracer = threadAndTimeTracer $ show >$< stdoutTracer
 
 threadAndTimeTracer :: Tracer IO (WithThreadAndTime a) -> Tracer IO a
-threadAndTimeTracer tr = Tracer $ \s -> do
+threadAndTimeTracer tr = mkTracer $ \s -> do
     !now <- getCurrentTime
     !tid <- myThreadId
     traceWith tr $ WithThreadAndTime now tid s
diff --git a/ouroboros-network/framework/lib/Data/Cache.hs b/ouroboros-network/framework/lib/Data/Cache.hs
index 27c2a32e022..3f7211c81a0 100644
--- a/ouroboros-network/framework/lib/Data/Cache.hs
+++ b/ouroboros-network/framework/lib/Data/Cache.hs
@@ -27,7 +27,7 @@ withCacheA (Cache a) a' action =
 -- | Trace with cache only performs the tracing when the cached value is
 -- different than the most recent one.
 --
-traceWithCache :: (Applicative m, Eq a) => Tracer m a -> Cache a -> a -> m ()
+traceWithCache :: (Monad m, Eq a) => Tracer m a -> Cache a -> a -> m ()
 traceWithCache tracer cache a =
     withCacheA cache a (traceWith tracer)
 
@@ -35,7 +35,7 @@ traceWithCache tracer cache a =
 -- different than the most recent one. And applies a function to the cache
 -- value before tracing.
 --
-mapTraceWithCache :: (Applicative m, Eq a)
+mapTraceWithCache :: (Monad m, Eq a)
                   => (a -> b) -> Tracer m b -> Cache a -> a -> m ()
 mapTraceWithCache f tracer cache a =
     withCacheA cache a (traceWith tracer . f)
diff --git a/ouroboros-network/framework/lib/Ouroboros/Network/InboundGovernor.hs b/ouroboros-network/framework/lib/Ouroboros/Network/InboundGovernor.hs
index 7900fb31623..7e515d9fe99 100644
--- a/ouroboros-network/framework/lib/Ouroboros/Network/InboundGovernor.hs
+++ b/ouroboros-network/framework/lib/Ouroboros/Network/InboundGovernor.hs
@@ -51,7 +51,7 @@ import Control.Monad.Class.MonadFork
 import Control.Monad.Class.MonadThrow
 import Control.Monad.Class.MonadTime.SI
 import Control.Monad.Class.MonadTimer.SI
-import Control.Tracer (Tracer (..), traceWith)
+import Control.Tracer (Tracer, mkTracer, traceWith)
 
 import Data.Bifunctor (first)
 import Data.ByteString.Lazy (ByteString)
@@ -603,7 +603,7 @@ inboundGovernorMuxTracer
   -> StrictTVar m (StrictMaybe ResponderCounters)
   -> Tracer m (Mux.WithBearer (ConnectionId peerAddr) Mux.Trace)
 inboundGovernorMuxTracer infoChannel connectionDataFlow stateVar activeVar countersVar =
-  Tracer \(Mux.WithBearer peer trace) -> do
+  mkTracer \(Mux.WithBearer peer trace) -> do
     -- hello from muxer main thread
     -- code here is running in the context of the connection handler/muxer
     -- so care must be taken not to deadlock ourselves
diff --git a/ouroboros-network/framework/lib/Ouroboros/Network/Socket.hs b/ouroboros-network/framework/lib/Ouroboros/Network/Socket.hs
index 989a180596e..1ee33026c87 100644
--- a/ouroboros-network/framework/lib/Ouroboros/Network/Socket.hs
+++ b/ouroboros-network/framework/lib/Ouroboros/Network/Socket.hs
@@ -73,7 +73,6 @@ import Control.Monad.Class.MonadTimer.SI
 import Data.Bifunctor (first)
 import Data.ByteString.Lazy qualified as BL
 import Data.Foldable (traverse_)
-import Data.Functor.Contravariant ((>$<))
 import Data.Hashable
 import Data.Monoid.Synchronisation (FirstToFinish (..))
 import Data.Typeable (Typeable)
@@ -118,7 +117,7 @@ data NetworkConnectTracers m addr vNumber = NetworkConnectTracers {
       -- negotiation mismatches.
     }
 
-nullNetworkConnectTracers :: Applicative m
+nullNetworkConnectTracers :: Monad m
                           => NetworkConnectTracers m addr vNumber
 nullNetworkConnectTracers = NetworkConnectTracers {
       nctMuxTracers      = Mx.nullTracers,
diff --git a/ouroboros-network/framework/sim-tests/Test/Ouroboros/Network/RateLimiting.hs b/ouroboros-network/framework/sim-tests/Test/Ouroboros/Network/RateLimiting.hs
index 118f95540b9..c16302aedc2 100644
--- a/ouroboros-network/framework/sim-tests/Test/Ouroboros/Network/RateLimiting.hs
+++ b/ouroboros-network/framework/sim-tests/Test/Ouroboros/Network/RateLimiting.hs
@@ -12,7 +12,7 @@ import Control.Monad.Class.MonadAsync
 import Control.Monad.Class.MonadTime.SI
 import Control.Monad.Class.MonadTimer.SI
 import Control.Monad.IOSim
-import Control.Tracer (Tracer (..), contramapM)
+import Control.Tracer (Tracer, contramapM, mkTracer)
 import Data.List (scanl')
 
 import Ouroboros.Network.Server.RateLimiting
@@ -202,7 +202,7 @@ runRateLimitExperiment :: AcceptedConnectionsLimit
 runRateLimitExperiment policy events =
     selectTraceEventsDynamic
       $ runSimTrace
-      $ rateLimittingExperiment (Tracer traceM) policy events
+      $ rateLimittingExperiment (mkTracer traceM) policy events
 
 
 --
diff --git a/ouroboros-network/framework/sim-tests/Test/Ouroboros/Network/RawBearer.hs b/ouroboros-network/framework/sim-tests/Test/Ouroboros/Network/RawBearer.hs
index c2ae701e525..3317811817e 100644
--- a/ouroboros-network/framework/sim-tests/Test/Ouroboros/Network/RawBearer.hs
+++ b/ouroboros-network/framework/sim-tests/Test/Ouroboros/Network/RawBearer.hs
@@ -8,7 +8,7 @@ module Test.Ouroboros.Network.RawBearer where
 
 import Control.Monad.Class.MonadSay
 import Control.Monad.IOSim hiding (liftST)
-import Control.Tracer (Tracer (..), nullTracer)
+import Control.Tracer (Tracer, mkTracer, nullTracer)
 
 import Ouroboros.Network.Snocket
 import Simulation.Network.Snocket as SimSnocket
@@ -25,7 +25,7 @@ tests = testGroup "Ouroboros.Network.RawBearer"
   ]
 
 iosimTracer :: forall s. Tracer (IOSim s) String
-iosimTracer = Tracer say
+iosimTracer = mkTracer say
 
 ioTracer :: Tracer IO String
 ioTracer = nullTracer
diff --git a/ouroboros-network/framework/sim-tests/Test/Ouroboros/Network/Server/Sim.hs b/ouroboros-network/framework/sim-tests/Test/Ouroboros/Network/Server/Sim.hs
index 47085e89ff4..9e72ab1b5aa 100644
--- a/ouroboros-network/framework/sim-tests/Test/Ouroboros/Network/Server/Sim.hs
+++ b/ouroboros-network/framework/sim-tests/Test/Ouroboros/Network/Server/Sim.hs
@@ -40,7 +40,7 @@ import Control.Monad.Class.MonadTime.SI
 import Control.Monad.Class.MonadTimer.SI
 import Control.Monad.Fix (MonadFix)
 import Control.Monad.IOSim
-import Control.Tracer (Tracer (..), nullTracer)
+import Control.Tracer (Tracer, mkTracer, nullTracer)
 
 import Codec.Serialise.Class (Serialise)
 import Data.Bifoldable
@@ -1432,7 +1432,7 @@ prop_connection_manager_counters (Fixed rnd) serverAcc (ArbDataFlow dataFlow)
          else (duplexConns, unidirectionalConns, inboundConns + outboundConns - duplexConns)
 
     networkStateTracer getState =
-      Tracer $ \_ -> getState >>= traceM
+      mkTracer $ \_ -> getState >>= traceM
 
     sim :: IOSim s ()
     sim = do
diff --git a/ouroboros-network/lib/Ouroboros/Network/Diffusion/Types.hs b/ouroboros-network/lib/Ouroboros/Network/Diffusion/Types.hs
index c89525aed47..199b93fbcff 100644
--- a/ouroboros-network/lib/Ouroboros/Network/Diffusion/Types.hs
+++ b/ouroboros-network/lib/Ouroboros/Network/Diffusion/Types.hs
@@ -305,7 +305,7 @@ data Tracers ntnAddr ntnVersion ntnVersionData
     }
 
 
-nullTracers :: Applicative m
+nullTracers :: Monad m
             => Tracers ntnAddr ntnVersion ntnVersionData
                        ntcAddr ntcVersion ntcVersionData
                        extraState extraDebugState
diff --git a/ouroboros-network/lib/Ouroboros/Network/PeerSelection/PeerMetric.hs b/ouroboros-network/lib/Ouroboros/Network/PeerSelection/PeerMetric.hs
index 78ceefca3c3..6bcd7b6d9aa 100644
--- a/ouroboros-network/lib/Ouroboros/Network/PeerSelection/PeerMetric.hs
+++ b/ouroboros-network/lib/Ouroboros/Network/PeerSelection/PeerMetric.hs
@@ -35,7 +35,7 @@ import Control.DeepSeq (NFData (..))
 import Control.Monad (when)
 import Control.Monad.Class.MonadSTM
 import Control.Monad.Class.MonadTime.SI
-import Control.Tracer (Tracer (..), contramap, nullTracer)
+import Control.Tracer (Tracer, contramap, mkTracer, nullTracer)
 import Data.Bifunctor (Bifunctor (..))
 import Data.IntPSQ (IntPSQ)
 import Data.IntPSQ qualified as IntPSQ
@@ -320,7 +320,7 @@ peerRegistryTracer :: forall p m.
                    => PeerMetrics m p
                    -> Tracer (STM m) (TraceLabelPeer p SlotNo)
 peerRegistryTracer PeerMetrics { peerMetricsVar } =
-    Tracer $ \(TraceLabelPeer peer slotNo) -> do
+    mkTracer $ \(TraceLabelPeer peer slotNo) -> do
       -- order matters: 'insertPeer' must access the previous value of
       -- lastSeenRegistry
       modifyTVar peerMetricsVar $ updateLastSlot slotNo
@@ -372,7 +372,7 @@ metricsTracer
     -> PeerMetricsConfiguration
     -> Tracer (STM m) (TraceLabelPeer p (SlotNo, Time))
 metricsTracer getMetrics writeMetrics PeerMetricsConfiguration { maxEntriesToTrack } =
-    Tracer $ \(TraceLabelPeer !peer (!slot, !time)) -> do
+    mkTracer $ \(TraceLabelPeer !peer (!slot, !time)) -> do
       metrics <- getMetrics
       let !k = slotToInt slot
           !v = (peer, time)
diff --git a/ouroboros-network/ouroboros-network.cabal b/ouroboros-network/ouroboros-network.cabal
index 74de4ca71a5..21f8f8a8333 100644
--- a/ouroboros-network/ouroboros-network.cabal
+++ b/ouroboros-network/ouroboros-network.cabal
@@ -143,7 +143,7 @@ library api-tests-lib
     Ouroboros.Network.Mock.ConcreteBlock
 
   build-depends:
-    QuickCheck,
+    QuickCheck < 2.18,
     base,
     bytestring,
     cardano-slotting:testlib ^>=0.2.0,
@@ -169,7 +169,7 @@ test-suite api-tests
     Test.Ouroboros.Network.PeerSelection.RelayAccessPoint
 
   build-depends:
-    QuickCheck,
+    QuickCheck < 2.18,
     aeson,
     base >=4.14 && <4.23,
     bytestring,
@@ -442,7 +442,7 @@ library tests-lib
     TypeInType
 
   build-depends:
-    QuickCheck,
+    QuickCheck < 2.18,
     base >=4.14 && <4.23,
     cborg >=0.2.1 && <0.3,
     containers,
@@ -480,7 +480,7 @@ test-suite tests-lib-tests
   hs-source-dirs: tests-lib/tests
   other-modules: Test.Ouroboros.Network.Data.AbsBearerInfo.Test
   build-depends:
-    QuickCheck,
+    QuickCheck < 2.18,
     base >=4.14 && <4.23,
     ouroboros-network:tests-lib,
     tasty,
@@ -506,7 +506,7 @@ library framework-tests-lib
     Test.Ouroboros.Network.RawBearer.Utils
 
   build-depends:
-    QuickCheck,
+    QuickCheck < 2.18,
     base >=4.14 && <4.23,
     bytestring,
     cborg,
@@ -539,7 +539,7 @@ test-suite framework-sim-tests
     Test.Simulation.Network.Snocket
 
   build-depends:
-    QuickCheck,
+    QuickCheck < 2.18,
     base >=4.14 && <4.23,
     bytestring,
     cborg,
@@ -583,7 +583,7 @@ test-suite framework-io-tests
     Test.Ouroboros.Network.Socket
 
   build-depends:
-    QuickCheck,
+    QuickCheck < 2.18,
     base >=4.14 && <4.23,
     bytestring,
     contra-tracer,
@@ -738,7 +738,7 @@ executable demo-tx-submission
     Demo.TxSubmission.Outbound
 
   build-depends:
-    QuickCheck,
+    QuickCheck < 2.18,
     async,
     base,
     bytestring,
@@ -903,7 +903,7 @@ library protocols-tests-lib
     Test.Ouroboros.Network.Protocol.Utils
 
   build-depends:
-    QuickCheck,
+    QuickCheck < 2.18,
     base >=4.14 && <4.23,
     bytestring,
     cardano-strict-containers,
@@ -948,7 +948,7 @@ library ouroboros-network-tests-lib
   visibility: public
   hs-source-dirs: tests/lib
   build-depends:
-    QuickCheck,
+    QuickCheck < 2.18,
     aeson,
     array,
     base >=4.14 && <4.23,
@@ -1047,7 +1047,7 @@ test-suite ouroboros-network-io-tests
     Test.Ouroboros.Network.Socket
 
   build-depends:
-    QuickCheck,
+    QuickCheck < 2.18,
     base >=4.14 && <4.23,
     bytestring,
     cborg,
diff --git a/ouroboros-network/tests-lib/lib/Test/Ouroboros/Network/Utils.hs b/ouroboros-network/tests-lib/lib/Test/Ouroboros/Network/Utils.hs
index 3199eeacf50..48b68f6eee3 100644
--- a/ouroboros-network/tests-lib/lib/Test/Ouroboros/Network/Utils.hs
+++ b/ouroboros-network/tests-lib/lib/Test/Ouroboros/Network/Utils.hs
@@ -48,7 +48,7 @@ import GHC.Real
 import Control.Monad.Class.MonadSay
 import Control.Monad.Class.MonadTime.SI
 import Control.Monad.IOSim (IOSim, traceM)
-import Control.Tracer (Contravariant (contramap), Tracer (..), contramapM)
+import Control.Tracer (Contravariant (contramap), Tracer, contramapM, mkTracer)
 
 import Data.Bitraversable (bimapAccumR)
 import Data.List (delete, nub)
@@ -198,7 +198,7 @@ data WithTime event = WithTime {
 instance Show event => Show (WithTime event) where
   show (WithTime (Time t) ev) = show t <> "@ " <> show ev
 
-tracerWithName :: name -> Tracer m (WithName name a) -> Tracer m a
+tracerWithName :: Monad m => name -> Tracer m (WithName name a) -> Tracer m a
 tracerWithName name = contramap (WithName name)
 
 tracerWithTime :: MonadMonotonicTime m => Tracer m (WithTime a) -> Tracer m a
@@ -266,17 +266,17 @@ instance (Eq a, Arbitrary a) => Arbitrary (DistinctNEList a) where
 -- | Trace to `stderr` via `Debug.Tracer` API.
 --
 debugTracer :: ( Show a, Applicative m) => Tracer m a
-debugTracer = Tracer Debug.traceShowM
+debugTracer = mkTracer Debug.traceShowM
 
 -- | Trace using `MonadSay` instance.
 --
 sayTracer :: ( Show a, MonadSay m) => Tracer m a
-sayTracer = Tracer (say . show)
+sayTracer = mkTracer (say . show)
 
 -- | Dynamic tracer for `IOSim` using `traceM`.
 --
 dynamicTracer :: Typeable a => Tracer (IOSim s) a
-dynamicTracer = Tracer traceM
+dynamicTracer = mkTracer traceM
 
 --
 -- Nightly tests
diff --git a/ouroboros-network/tests/io/Test/Ouroboros/Network/Socket.hs b/ouroboros-network/tests/io/Test/Ouroboros/Network/Socket.hs
index 788c1cf2ea1..c791550aa30 100644
--- a/ouroboros-network/tests/io/Test/Ouroboros/Network/Socket.hs
+++ b/ouroboros-network/tests/io/Test/Ouroboros/Network/Socket.hs
@@ -15,7 +15,6 @@
 module Test.Ouroboros.Network.Socket (tests) where
 
 import Data.ByteString.Lazy qualified as BL
-import Data.Functor.Contravariant ((>$<))
 import Data.Void (Void)
 import GHC.Generics (Generic)
 import Network.Socket qualified as Socket
@@ -344,7 +343,7 @@ _verboseTracer :: Show a => Tracer IO a
 _verboseTracer = threadAndTimeTracer $ show >$< stdoutTracer
 
 threadAndTimeTracer :: Tracer IO (WithThreadAndTime a) -> Tracer IO a
-threadAndTimeTracer tr = Tracer $ \s -> do
+threadAndTimeTracer tr = mkTracer $ \s -> do
     !now <- getCurrentTime
     !tid <- myThreadId
     traceWith tr $ WithThreadAndTime now tid s
diff --git a/ouroboros-network/tests/lib/Test/Ouroboros/Network/KeepAlive.hs b/ouroboros-network/tests/lib/Test/Ouroboros/Network/KeepAlive.hs
index f011d5417f0..e364a007b97 100644
--- a/ouroboros-network/tests/lib/Test/Ouroboros/Network/KeepAlive.hs
+++ b/ouroboros-network/tests/lib/Test/Ouroboros/Network/KeepAlive.hs
@@ -192,4 +192,4 @@ prop_keepAlive_convergence nd seed =
         g >= low && g <= high
 
 dynamicTracer :: Typeable a => Tracer (IOSim s) a
-dynamicTracer = Tracer traceM
+dynamicTracer = mkTracer traceM
diff --git a/ouroboros-network/tests/lib/Test/Ouroboros/Network/LedgerPeers.hs b/ouroboros-network/tests/lib/Test/Ouroboros/Network/LedgerPeers.hs
index fdf34165fb5..a4ea863a4ad 100644
--- a/ouroboros-network/tests/lib/Test/Ouroboros/Network/LedgerPeers.hs
+++ b/ouroboros-network/tests/lib/Test/Ouroboros/Network/LedgerPeers.hs
@@ -25,7 +25,7 @@ import Control.Monad.Class.MonadThrow
 import Control.Monad.Class.MonadTime.SI
 import Control.Monad.Class.MonadTimer.SI
 import Control.Monad.IOSim hiding (SimResult)
-import Control.Tracer (Tracer (..), nullTracer, traceWith)
+import Control.Tracer (Tracer, mkTracer, nullTracer, traceWith)
 import Data.Aeson
 import Data.Aeson.Types as Aeson
 import Data.ByteString.Builder (toLazyByteString, word64BE)
@@ -295,7 +295,7 @@ prop_pick100 seed (NonNegative n) ledgerPeersKind (MockRoots _ dnsMapScript _ _)
           withLedgerPeers
                 PeerActionsDNS { paToPeerAddr = curry IP.toSockAddr,
                                  paDnsActions = mockDNSActions
-                                                   (Tracer traceM)
+                                                   (mkTracer traceM)
                                                    LookupReqAOnly
                                                    (curry IP.toSockAddr)
                                                    dnsMapVar
@@ -363,7 +363,7 @@ prop_pick (LedgerPools lps) ledgerPeersKind count seed (MockRoots _ dnsMapScript
           withLedgerPeers
                 PeerActionsDNS { paToPeerAddr = curry IP.toSockAddr,
                                  paDnsActions = mockDNSActions
-                                                  (Tracer traceM)
+                                                  (mkTracer traceM)
                                                   LookupReqAOnly
                                                   (curry IP.toSockAddr)
                                                   dnsMapVar
@@ -781,7 +781,7 @@ threadAndTimeTracer :: forall a m.
                        , MonadMonotonicTime m
                        )
                     => Tracer m (WithThreadAndTime a) -> Tracer m a
-threadAndTimeTracer tr = Tracer $ \s -> do
+threadAndTimeTracer tr = mkTracer $ \s -> do
     !now <- getMonotonicTime
     !tid <- show <$> myThreadId
     traceWith tr $! WithThreadAndTime now tid s
diff --git a/ouroboros-network/tests/lib/Test/Ouroboros/Network/Mux.hs b/ouroboros-network/tests/lib/Test/Ouroboros/Network/Mux.hs
index f39d3f550fc..b8c5e35588f 100644
--- a/ouroboros-network/tests/lib/Test/Ouroboros/Network/Mux.hs
+++ b/ouroboros-network/tests/lib/Test/Ouroboros/Network/Mux.hs
@@ -64,7 +64,7 @@ activeTracer = nullTracer
 --activeTracer = show >$< sayTracer
 
 _sayTracer :: MonadSay m => Tracer m String
-_sayTracer = Tracer say
+_sayTracer = mkTracer say
 
 
 testProtocols :: RunMiniProtocolWithMinimalCtx appType addr bytes m a b
diff --git a/ouroboros-network/tests/lib/Test/Ouroboros/Network/PeerSelection/PeerMetric.hs b/ouroboros-network/tests/lib/Test/Ouroboros/Network/PeerSelection/PeerMetric.hs
index 1455faf7811..247f36551e9 100644
--- a/ouroboros-network/tests/lib/Test/Ouroboros/Network/PeerSelection/PeerMetric.hs
+++ b/ouroboros-network/tests/lib/Test/Ouroboros/Network/PeerSelection/PeerMetric.hs
@@ -21,7 +21,7 @@ import Control.DeepSeq (NFData (..))
 import Control.Monad (when)
 import Control.Monad.Class.MonadTime.SI
 import Control.Monad.Class.MonadTimer.SI
-import Control.Tracer (Tracer (..), traceWith)
+import Control.Tracer (Tracer, mkTracer, traceWith)
 
 import Data.Foldable as Foldable (foldl', foldr')
 import Data.List (sortOn)
@@ -254,7 +254,7 @@ prop_insert_peer script =
     config = PeerMetricsConfiguration { maxEntriesToTrack = 180 }
 
     sim :: IOSim s ()
-    sim = simulatePeerMetricScript (Tracer traceM) config script
+    sim = simulatePeerMetricScript (mkTracer traceM) config script
 
     -- drop first 90 slots
     trace :: [PeerMetricsTrace]
@@ -319,7 +319,7 @@ prop_metrics_are_bounded script =
     config = PeerMetricsConfiguration { maxEntriesToTrack = 180 }
 
     sim :: IOSim s ()
-    sim = simulatePeerMetricScript (Tracer traceM) config script
+    sim = simulatePeerMetricScript (mkTracer traceM) config script
 
     trace :: [PeerMetricsTrace]
     trace = selectTraceEventsDynamic (runSimTrace sim)
@@ -393,7 +393,7 @@ prop_bounded_size (Positive maxEntriesToTrack) script =
     config = PeerMetricsConfiguration { maxEntriesToTrack }
 
     sim :: IOSim s ()
-    sim = simulatePeerMetricScript (Tracer traceM) config script
+    sim = simulatePeerMetricScript (mkTracer traceM) config script
 
     trace :: [PeerMetricsTrace]
     trace = selectTraceEventsDynamic (runSimTrace sim)
@@ -475,7 +475,7 @@ prop_simScript script =
     config = PeerMetricsConfiguration { maxEntriesToTrack = 500 }
 
     sim :: IOSim s ()
-    sim = simulatePeerMetricScriptWithoutDelays (Tracer traceM) config script
+    sim = simulatePeerMetricScriptWithoutDelays (mkTracer traceM) config script
 
     trace :: [PeerMetricsTrace]
     trace = selectTraceEventsDynamic (runSimTrace sim)
diff --git a/ouroboros-network/tests/lib/Test/Ouroboros/Network/PeerSelection/RootPeersDNS.hs b/ouroboros-network/tests/lib/Test/Ouroboros/Network/PeerSelection/RootPeersDNS.hs
index 52ea03ea6fe..dcc14fb8163 100644
--- a/ouroboros-network/tests/lib/Test/Ouroboros/Network/PeerSelection/RootPeersDNS.hs
+++ b/ouroboros-network/tests/lib/Test/Ouroboros/Network/PeerSelection/RootPeersDNS.hs
@@ -68,7 +68,7 @@ import Control.Monad.Class.MonadTime.SI
 import Control.Monad.Class.MonadTimer.SI
 import Control.Monad.Class.MonadTimer.SI qualified as MonadTimer
 import Control.Monad.IOSim
-import Control.Tracer (Tracer (Tracer), contramap, nullTracer, traceWith)
+import Control.Tracer (Tracer, contramap, mkTracer, nullTracer, traceWith)
 
 import Ouroboros.Network.ConnectionManager.Types (Provenance (Outbound))
 import Ouroboros.Network.DiffusionMode
@@ -607,10 +607,10 @@ mockResolveLedgerPeers tracer (MockRoots _ _ publicRootPeers dnsMapScript)
 type TestTraceEvent a = Either a DNSTrace
 
 tracerTraceLocalRoots :: Tracer (IOSim s) (TestTraceEvent (TraceLocalRootPeers () SockAddr))
-tracerTraceLocalRoots = Tracer traceM
+tracerTraceLocalRoots = mkTracer traceM
 
 tracerTracePublicRoots :: Tracer (IOSim s) (TestTraceEvent TracePublicRootPeers)
-tracerTracePublicRoots = Tracer traceM
+tracerTracePublicRoots = mkTracer traceM
 
 selectTestTraceEvents :: (Typeable b) => SimTrace a
                       -> [(Time, TestTraceEvent b)]
@@ -1097,8 +1097,8 @@ prop_retryResource (NonEmpty delays0) as =
     delays = getDNSTimeout <$> NonEmpty.fromList delays0
 
     tracer :: Tracer (IOSim s) Int
-    tracer = Tracer (\a -> getMonotonicTime >>= \t -> traceM (t, a))
-          <> Tracer (\a -> getMonotonicTime >>= \t -> say (show (t, a)))
+    tracer = mkTracer (\a -> getMonotonicTime >>= \t -> traceM (t, a))
+          <> mkTracer (\a -> getMonotonicTime >>= \t -> say (show (t, a)))
 
     resource :: Resource (IOSim s) Int
     resource = retryResource nullTracer delays
diff --git a/ouroboros-network/tests/lib/Test/Ouroboros/Network/TxSubmission/Types.hs b/ouroboros-network/tests/lib/Test/Ouroboros/Network/TxSubmission/Types.hs
index 3ca190ce802..908b22bfa57 100644
--- a/ouroboros-network/tests/lib/Test/Ouroboros/Network/TxSubmission/Types.hs
+++ b/ouroboros-network/tests/lib/Test/Ouroboros/Network/TxSubmission/Types.hs
@@ -43,7 +43,7 @@ import Control.Monad.Class.MonadThrow
 import Control.Monad.Class.MonadTime.SI
 import Control.Monad.Class.MonadTimer.SI
 import Control.Monad.IOSim hiding (SimResult)
-import Control.Tracer (Tracer (..), traceWith)
+import Control.Tracer (Tracer, mkTracer, traceWith)
 
 import Codec.CBOR.Decoding qualified as CBOR
 import Codec.CBOR.Encoding qualified as CBOR
@@ -331,7 +331,7 @@ threadAndTimeTracer :: forall a m.
                        , MonadMonotonicTime m
                        )
                     => Tracer m (WithThreadAndTime a) -> Tracer m a
-threadAndTimeTracer tr = Tracer $ \s -> do
+threadAndTimeTracer tr = mkTracer $ \s -> do
     !now <- getMonotonicTime
     !tid <- myThreadId
     traceWith tr $ WithThreadAndTime now (show tid) s