diff --git a/tools/pyosmium-get-changes b/tools/pyosmium-get-changes
index f86ffe3..f343e37 100755
--- a/tools/pyosmium-get-changes
+++ b/tools/pyosmium-get-changes
@@ -166,7 +166,7 @@ if __name__ == '__main__':
               needs to begiven."""))
             exit(1)
 
-        with open(opt.start_file, 'r') as f:
+        with open(options.start_file, 'r') as f:
             seq = f.readline()
             options.start = ReplicationStart_from_id(seq)