diff --git a/src/Playwright/Transport/Connection.cs b/src/Playwright/Transport/Connection.cs
index 7403654630..65aa7c9971 100644
--- a/src/Playwright/Transport/Connection.cs
+++ b/src/Playwright/Transport/Connection.cs
@@ -440,7 +440,11 @@ internal async Task<T> WrapApiCallAsync<T>(Func<Task<T>> action, bool isInternal
                 var sf = st.GetFrame(i);
                 string fileName = sf.GetFileName();
                 string cSharpNamespace = sf.GetMethod().ReflectedType.Namespace;
-                bool playwrightInternal = cSharpNamespace == "Microsoft.Playwright" || cSharpNamespace.StartsWith("Microsoft.Playwright.Core", StringComparison.InvariantCultureIgnoreCase) || cSharpNamespace.StartsWith("Microsoft.Playwright.Transport", StringComparison.InvariantCultureIgnoreCase) || cSharpNamespace.StartsWith("Microsoft.Playwright.Helpers", StringComparison.InvariantCultureIgnoreCase);
+                bool playwrightInternal = cSharpNamespace != null &&
+                                          (cSharpNamespace == "Microsoft.Playwright" ||
+                                          cSharpNamespace.StartsWith("Microsoft.Playwright.Core", StringComparison.InvariantCultureIgnoreCase) ||
+                                          cSharpNamespace.StartsWith("Microsoft.Playwright.Transport", StringComparison.InvariantCultureIgnoreCase) ||
+                                          cSharpNamespace.StartsWith("Microsoft.Playwright.Helpers", StringComparison.InvariantCultureIgnoreCase));
                 if (string.IsNullOrEmpty(fileName) && !playwrightInternal)
                 {
                     continue;