diff --git a/lib/core/option.py b/lib/core/option.py
index 622214d19..5a81232db 100644
--- a/lib/core/option.py
+++ b/lib/core/option.py
@@ -814,7 +814,7 @@ def _setDBMS():
 
     if conf.dbms not in SUPPORTED_DBMS:
         errMsg = "you provided an unsupported back-end database management "
-        errMsg += "system. The supported DBMS are %s. " % ', '.join([d for d in DBMS_DICT])
+        errMsg += "system. The supported DBMS are %s. " % ', '.join([_ for _ in DBMS_DICT])
         errMsg += "If you do not know the back-end DBMS, do not provide "
         errMsg += "it and sqlmap will fingerprint it for you."
         raise SqlmapUnsupportedDBMSException(errMsg)