diff --git a/hgdemandimport/__init__.py b/hgdemandimport/__init__.py
--- a/hgdemandimport/__init__.py
+++ b/hgdemandimport/__init__.py
@@ -66,6 +66,9 @@ IGNORES = {
 if _pypy:
     # _ctypes.pointer is shadowed by "from ... import pointer" (PyPy 5)
     IGNORES.add('_ctypes.pointer')
+    # pure Python module on PyPy, must be loaded to raise ModuleNotFoundError
+    # on non-Windows platforms
+    IGNORES.add('msvcrt')
 
 demandimport.init(IGNORES)