diff --git a/vendor/runtime-fixer b/vendor/runtime-fixer
index 4ee1e41..0162518 100755
--- a/vendor/runtime-fixer
+++ b/vendor/runtime-fixer
@@ -4,7 +4,7 @@ import sys
 
 runtime_file = sys.argv[1]
 
-with open(req_file, 'r') as f:
+with open(runtime_file, 'r') as f:
     r = f.read().strip()
 
 with open(runtime_file, 'w') as f: