diff --git a/pkg/openai/keymgr.py b/pkg/openai/keymgr.py
index 965a022d..5947c0a1 100644
--- a/pkg/openai/keymgr.py
+++ b/pkg/openai/keymgr.py
@@ -78,6 +78,8 @@ class KeysManager:
 
         self.usage[md5] += round(int((len(new_content.encode('utf-8')) - len(new_content)) / 2 + len(new_content))*salt_rate)
 
+        self.usage[md5] = int(self.usage[md5])
+
         if self.usage[md5] >= self.api_key_usage_threshold:
             switch_result, key_name = self.auto_switch()