diff --git a/hgdemandimport/demandimportpy3.py b/hgdemandimport/demandimportpy3.py
--- a/hgdemandimport/demandimportpy3.py
+++ b/hgdemandimport/demandimportpy3.py
@@ -53,9 +53,13 @@ class _lazyloaderex(importlib.util.LazyL
 
 # This is 3.6+ because with Python 3.5 it isn't possible to lazily load
 # extensions. See the discussion in https://bugs.python.org/issue26186 for more.
-_extensions_loader = _lazyloaderex.factory(
-    importlib.machinery.ExtensionFileLoader
-)
+if sys.version_info[0:2] >= (3, 6):
+    _extensions_loader = _lazyloaderex.factory(
+        importlib.machinery.ExtensionFileLoader
+    )
+else:
+    _extensions_loader = importlib.machinery.ExtensionFileLoader
+
 _bytecode_loader = _lazyloaderex.factory(
     importlib.machinery.SourcelessFileLoader
 )