diff --git a/Lib/whichdb.py b/Lib/whichdb.py
index 5806118..4396321 100644
--- a/Lib/whichdb.py
+++ b/Lib/whichdb.py
@@ -26,6 +26,7 @@
         pass
 
     # Check for dumbdbm next -- this has a .dir and and a .dat file
+    try:
         f = open(filename + ".dat", "rb")
         f.close()
         f = open(filename + ".dir", "rb")