diff --git a/beetsplug/duplicates.py b/beetsplug/duplicates.py
index 63ce001d3..29a01220f 100644
--- a/beetsplug/duplicates.py
+++ b/beetsplug/duplicates.py
@@ -52,7 +52,8 @@ def _checksum(item, prog):
     output as flexattr on a key that is the name of the program, and
     return the key, checksum tuple.
     """
-    args = shlex.split(prog.format(file=item.path))
+    args = [p.format(file=item.path) for p in shlex.split(prog)]
+    print args
     key = args[0]
     checksum = getattr(item, key, False)
     if not checksum: