diff --git a/Lib/pkgutil.py b/Lib/pkgutil.py
index 932abbc..8e062a4 100644
--- a/Lib/pkgutil.py
+++ b/Lib/pkgutil.py
@@ -466,6 +466,8 @@
     platform-specific special import locations such as the Windows registry.
     """
     for importer in iter_importers(fullname):
+        if importer is None:
+            continue
         loader = importer.find_module(fullname)
         if loader is not None:
             return loader