diff --git a/heroku/modules/executor.py b/heroku/modules/executor.py
index 8ae4fb6..7ffaa2f 100644
--- a/heroku/modules/executor.py
+++ b/heroku/modules/executor.py
@@ -117,9 +117,9 @@ class Executor(loader.Module):
 
         if result:
             if not cerr:
-                result = self.strings["result_no_error"].format(result={result})
+                result = self.strings["result_no_error"].format(result=result)
             else:
-                result = self.strings["result_error"].format(result={result})
+                result = self.strings["result_error"].format(result=result)
 
         if res or res == 0 or res == False and res is not None:
             result += self.strings["res_return"].format(res={res})