diff --git a/cabal.project b/cabal.project
index 77da1bec662..e83c97e16d6 100644
--- a/cabal.project
+++ b/cabal.project
@@ -18,7 +18,7 @@ index-state:
   , hackage.haskell.org 2024-12-10T16:20:07Z
 
   -- Bump this if you need newer packages from CHaP
-  , cardano-haskell-packages 2024-11-26T16:00:26Z
+  , cardano-haskell-packages 2026-04-11T06:29:42Z
 
 packages: ./cardano-ping
           ./monoidal-synchronisation
diff --git a/flake.lock b/flake.lock
index aa7cb1af133..163c07cf1bc 100644
--- a/flake.lock
+++ b/flake.lock
@@ -3,11 +3,11 @@
     "CHaP": {
       "flake": false,
       "locked": {
-        "lastModified": 1732639071,
-        "narHash": "sha256-XY+LlzuumeRovfBMXIPS90Trk7HTxpUMFFdL4bmMZDU=",
+        "lastModified": 1778533708,
+        "narHash": "sha256-l+e3z/HQUDKYv0/RoSBUw8vN8ivPjsGZbRMJojvWzfw=",
         "owner": "intersectmbo",
         "repo": "cardano-haskell-packages",
-        "rev": "6df7fca74cc3a34babfa7ce7cb4b7a8c72c70982",
+        "rev": "b7677707212c57986ce6342e8d4ae7415fe2ec08",
         "type": "github"
       },
       "original": {
diff --git a/ouroboros-network-protocols/testlib/Test/ChainGenerators.hs b/ouroboros-network-protocols/testlib/Test/ChainGenerators.hs
index 423a2cd0cca..06222a17fb7 100644
--- a/ouroboros-network-protocols/testlib/Test/ChainGenerators.hs
+++ b/ouroboros-network-protocols/testlib/Test/ChainGenerators.hs
@@ -97,16 +97,6 @@ tests = testGroup "Chain"
                              (mapSize (min 40) prop_shrink_TestChainFork)
   ]
 
-
-instance Arbitrary BlockNo where
-  arbitrary = BlockNo <$>
-                ((getPositive <$> arbitrary)
-                   `suchThat`
-                 (\n -> n < maxBound - 2^(32 :: Int)))
-               -- need some room, we're assuming we'll never wrap around 64bits
-
-  shrink (BlockNo n) = [ BlockNo n' | n' <- shrink n, n' > 0 ]
-
 instance Arbitrary ConcreteHeaderHash where
   arbitrary = HeaderHash <$> arbitrary