diff --git a/Lib/test/test_hashlib.py b/Lib/test/test_hashlib.py
index 6088307..86f20a7 100644
--- a/Lib/test/test_hashlib.py
+++ b/Lib/test/test_hashlib.py
@@ -102,7 +102,7 @@
         try:
             return importlib.import_module(module_name)
         except ModuleNotFoundError as error:
-            if self._warn_on_extension_import:
+            if self._warn_on_extension_import and module_name in builtin_hashes:
                 warnings.warn('Did a C extension fail to compile? %s' % error)
         return None