diff --git a/protocol/blockfetch/client_test.go b/protocol/blockfetch/client_test.go
index a2b54e9a..1cb19726 100644
--- a/protocol/blockfetch/client_test.go
+++ b/protocol/blockfetch/client_test.go
@@ -56,7 +56,7 @@ func runTest(
 	go func() {
 		err := <-mockConn.(*ouroboros_mock.Connection).ErrorChan()
 		if err != nil {
-			asyncErrChan <- fmt.Errorf("received unexpected error: %s", err)
+			asyncErrChan <- fmt.Errorf("received unexpected error: %w", err)
 		}
 		close(asyncErrChan)
 	}()
diff --git a/protocol/chainsync/client_test.go b/protocol/chainsync/client_test.go
index d158f561..9c9aa992 100644
--- a/protocol/chainsync/client_test.go
+++ b/protocol/chainsync/client_test.go
@@ -58,7 +58,7 @@ func runTest(
 	go func() {
 		err := <-mockConn.(*ouroboros_mock.Connection).ErrorChan()
 		if err != nil {
-			asyncErrChan <- fmt.Errorf("received unexpected error: %s", err)
+			asyncErrChan <- fmt.Errorf("received unexpected error: %w", err)
 		}
 		close(asyncErrChan)
 	}()
diff --git a/protocol/keepalive/client_test.go b/protocol/keepalive/client_test.go
index 85a7e075..dbd48bdf 100644
--- a/protocol/keepalive/client_test.go
+++ b/protocol/keepalive/client_test.go
@@ -146,7 +146,7 @@ func TestServerKeepaliveHandlingWithWrongResponse(t *testing.T) {
 			asyncErrChan <- errors.New("did not receive expected error")
 		} else {
 			if err.Error() != expectedErr {
-				asyncErrChan <- fmt.Errorf("did not receive expected error\n  got:    %s\n  wanted: %s", err, expectedErr)
+				asyncErrChan <- fmt.Errorf("did not receive expected error\n  got:    %v\n  wanted: %s", err, expectedErr)
 			}
 		}
 		close(asyncErrChan)
diff --git a/protocol/localstatequery/client_test.go b/protocol/localstatequery/client_test.go
index d4575eef..cedb2b68 100644
--- a/protocol/localstatequery/client_test.go
+++ b/protocol/localstatequery/client_test.go
@@ -80,7 +80,7 @@ func runTest(
 	go func() {
 		err := <-mockConn.(*ouroboros_mock.Connection).ErrorChan()
 		if err != nil {
-			asyncErrChan <- fmt.Errorf("received unexpected error: %s", err)
+			asyncErrChan <- fmt.Errorf("received unexpected error: %w", err)
 		}
 		close(asyncErrChan)
 	}()
diff --git a/protocol/localtxmonitor/client_test.go b/protocol/localtxmonitor/client_test.go
index b5ec45d9..b9935fcc 100644
--- a/protocol/localtxmonitor/client_test.go
+++ b/protocol/localtxmonitor/client_test.go
@@ -63,7 +63,7 @@ func runTest(
 	go func() {
 		err := <-mockConn.(*ouroboros_mock.Connection).ErrorChan()
 		if err != nil {
-			asyncErrChan <- fmt.Errorf("received unexpected error: %s", err)
+			asyncErrChan <- fmt.Errorf("received unexpected error: %w", err)
 		}
 		close(asyncErrChan)
 	}()
diff --git a/protocol/localtxsubmission/client_test.go b/protocol/localtxsubmission/client_test.go
index 6c038395..a90b65af 100644
--- a/protocol/localtxsubmission/client_test.go
+++ b/protocol/localtxsubmission/client_test.go
@@ -55,7 +55,7 @@ func runTest(
 	go func() {
 		err := <-mockConn.(*ouroboros_mock.Connection).ErrorChan()
 		if err != nil {
-			asyncErrChan <- fmt.Errorf("received unexpected error: %s", err)
+			asyncErrChan <- fmt.Errorf("received unexpected error: %w", err)
 		}
 		close(asyncErrChan)
 	}()