diff --git a/lib/request/inject.py b/lib/request/inject.py
index 110c8cc13..ff6b72349 100644
--- a/lib/request/inject.py
+++ b/lib/request/inject.py
@@ -421,7 +421,7 @@ def getValue(expression, blind=True, union=True, error=True, time=True, fromUser
 
     kb.safeCharEncode = False
 
-    if not kb.testMode and value is None and Backend.getDbms() and conf.dbmsHandler:
+    if not kb.testMode and value is None and Backend.getDbms() and conf.dbmsHandler and not conf.noCast and not conf.hexConvert:
         warnMsg = "in case of continuous data retrieval problems you are advised to try "
         warnMsg += "a switch '--no-cast' or switch '--hex'"
         singleTimeWarnMessage(warnMsg)