diff --git a/src/tools/msvc/vcregress.pl b/src/tools/msvc/vcregress.pl
index 29086ca..935ac5c 100644
--- a/src/tools/msvc/vcregress.pl
+++ b/src/tools/msvc/vcregress.pl
@@ -347,7 +347,7 @@ sub mangle_plpython3
 					s/([ [{])u'/$1'/g;
 					s/def next/def __next__/g;
 					s/LANGUAGE plpython2?u/LANGUAGE plpython3u/g;
-					s/EXTENSION ([^ ]*_)*plpython2?u/EXTENSION $1plpython3u/g;
+					s/EXTENSION ([^ ]*_*)plpython2?u/EXTENSION $1plpython3u/g;
 					s/installing required extension "plpython2u"/installing required extension "plpython3u"/g;
 				  }
 				  for ($contents);