diff --git a/tools/performance_try.py b/tools/performance_try.py
index 5e6404d..a319307 100755
--- a/tools/performance_try.py
+++ b/tools/performance_try.py
@@ -15,6 +15,7 @@
   args = sys.argv[1:]
   if len(args) != 1:
     print('Performance tracking takes exactly one argument, the name for display')
+    return 1
   subprocess.check_call([DART, SCRIPT, args[0]])
 
 if __name__ == '__main__':