diff --git a/lib/techniques/union/use.py b/lib/techniques/union/use.py
index 17364bfc3..ab3917285 100644
--- a/lib/techniques/union/use.py
+++ b/lib/techniques/union/use.py
@@ -91,7 +91,7 @@ def __oneShotUnionUse(expression, unpack=True, limited=False):
             elif Backend.isDbms(DBMS.MYSQL) and not kb.multiThreadMode:
                 warnMsg = "if the problem persists with 'None' values please try to use "
                 warnMsg += "hidden switch '--no-cast' (fixing problems with some collation "
-                warnMsg += "issues)"
+                warnMsg += "issues) or switch '--hex'"
                 singleTimeWarnMessage(warnMsg)
 
         conf.hashDB.write(expression, retVal)