diff --git a/python/_util.py b/python/_util.py
index ffd00ec4..7f3d51d4 100644
--- a/python/_util.py
+++ b/python/_util.py
@@ -208,7 +208,7 @@ def has_module(module_name):
     r"""
     (?P<model_name>
         (?:
-            [a-zA-Z0-9]+
+            [a-zA-Z0-9_]+
         )
         |
         (?: