diff --git a/pkg/wal/processor/transformer/wal_postgres_anon_rule_parser_test.go b/pkg/wal/processor/transformer/wal_postgres_anon_rule_parser_test.go
index 28d22b0f..6eb651bf 100644
--- a/pkg/wal/processor/transformer/wal_postgres_anon_rule_parser_test.go
+++ b/pkg/wal/processor/transformer/wal_postgres_anon_rule_parser_test.go
@@ -160,7 +160,13 @@ func TestAnonRuleParser_ParseAndValidate(t *testing.T) {
 
 	for _, tc := range tests {
 		t.Run(tc.name, func(t *testing.T) {
-			t.Parallel()
+			// dumpToFile subtests share a hardcoded filename
+			// (anonRulesFile) and a deferred os.Remove of that path. Running
+			// them in parallel races: the error-case's cleanup can delete
+			// the success-case's file before its os.Stat check.
+			if !tc.dumpToFile {
+				t.Parallel()
+			}
 
 			// Clean up any test files
 			defer func() {
diff --git a/pkg/wal/processor/webhook/notifier/webhook_notifier_test.go b/pkg/wal/processor/webhook/notifier/webhook_notifier_test.go
index 1ba9dbb8..373877bf 100644
--- a/pkg/wal/processor/webhook/notifier/webhook_notifier_test.go
+++ b/pkg/wal/processor/webhook/notifier/webhook_notifier_test.go
@@ -363,24 +363,29 @@ func TestNotifier(t *testing.T) {
 		close(doneChan)
 	}()
 
+	walEvent := &wal.Event{
+		CommitPosition: wal.CommitPosition("1"),
+		Data: &wal.Data{
+			Action: "I",
+		},
+	}
+
 	timer := time.NewTimer(5 * time.Second)
 	defer timer.Stop()
-	var processErr error
 	for {
 		select {
 		case <-doneChan:
-			require.ErrorIs(t, processErr, errTest)
+			// Notify has exited. The next ProcessWALEvent must observe the
+			// closed notifyDone and return the propagated error — assert on a
+			// fresh call rather than the previous loop iteration's result,
+			// which can be nil if Notify exited between PWE calls.
+			require.ErrorIs(t, n.ProcessWALEvent(context.Background(), walEvent), errTest)
 			return
 		case <-timer.C:
 			t.Error("test timeout")
 			return
 		default:
-			processErr = n.ProcessWALEvent(context.Background(), &wal.Event{
-				CommitPosition: wal.CommitPosition("1"),
-				Data: &wal.Data{
-					Action: "I",
-				},
-			})
+			_ = n.ProcessWALEvent(context.Background(), walEvent)
 		}
 	}
 }