--- a/Lib/whichdb.py
+++ b/Lib/whichdb.py
@@ -91,7 +91,7 @@ def whichdb(filename):
         return ""
 
     # Check for GNU dbm
-    if magic == 0x13579ace:
+    if magic in (0x13579ace, 0x13579acd, 0x13579acf):
         return "gdbm"
 
     # Check for old Berkeley db hash file format v2