diff --git a/R/pooled-request.R b/R/pooled-request.R
index de20ee7d..666b2378 100644
--- a/R/pooled-request.R
+++ b/R/pooled-request.R
@@ -78,7 +78,7 @@ PooledRequest <- R6Class(
       )
       handle_preflight(private$req_prep, private$handle)
 
-      curl::multi_add(
+      multi_add(
         handle = private$handle,
         pool = pool,
         data = private$path,
@@ -155,3 +155,15 @@ PooledRequest <- R6Class(
     }
   )
 )
+
+# Wrapper around curl::multi_add() so that the pooled (async) request pathway
+# has a mockable seam, mirroring curl_fetch() for the synchronous pathway.
+multi_add <- function(handle, pool, data, done, fail) {
+  curl::multi_add(
+    handle = handle,
+    pool = pool,
+    data = data,
+    done = done,
+    fail = fail
+  )
+}
diff --git a/tests/testthat/test-req-perform-connection.R b/tests/testthat/test-req-perform-connection.R
index 82d38b5c..047c886c 100644
--- a/tests/testthat/test-req-perform-connection.R
+++ b/tests/testthat/test-req-perform-connection.R
@@ -162,10 +162,10 @@ test_that("tracing works as expected", {
     resp <- req_perform_connection(request(url_build(parsed)))
     close(resp)
 
-    # A request with a curl error.
+    # A request with a curl error
     with_mocked_bindings(
       try(req_perform_connection(request("http://127.0.0.1")), silent = TRUE),
-      curl_fetch = function(...) abort("Failed to connect")
+      open = function(...) stop("Failed to connect")
     )
 
     # A request that triggers retries, generating three individual spans.
diff --git a/tests/testthat/test-req-promise.R b/tests/testthat/test-req-promise.R
index c31761d8..3c8231d5 100644
--- a/tests/testthat/test-req-promise.R
+++ b/tests/testthat/test-req-promise.R
@@ -191,7 +191,12 @@ test_that("tracing works as expected", {
         p <- req_perform_promise(request("http://127.0.0.1"))
         try(extract_promise(p), silent = TRUE)
       },
-      curl_fetch = function(...) abort("Failed to connect")
+      multi_add = function(handle, pool, data, done, fail) {
+        fail(structure(
+          "Failed to connect",
+          class = c("curl_error_couldnt_connect", "curl_error", "character")
+        ))
+      }
     )
 
     # A request with no parent context.