diff --git a/source/dnode/mnode/impl/src/mndStb.c b/source/dnode/mnode/impl/src/mndStb.c
index ccfad404d843503f134eaa006dcc5bd25551c46d..f80e7213248c98370c554d7354aa8a5f17e506b8 100644
--- a/source/dnode/mnode/impl/src/mndStb.c
+++ b/source/dnode/mnode/impl/src/mndStb.c
@@ -866,7 +866,7 @@ static int32_t mndCreateStb(SMnode *pMnode, SRpcMsg *pReq, SMCreateStbReq *pCrea
   mInfo("trans:%d, used to create stb:%s", pTrans->id, pCreate->name);
   if (mndBuildStbFromReq(pMnode, &stbObj, pCreate, pDb) != 0) goto _OVER;
 
-  char randStr[16] = {0};
+  char randStr[24] = {0};
   taosRandStr2(randStr, tListLen(randStr) - 1);
   SSchema *pSchema = &(stbObj.pTags[0]);
   sprintf(fullIdxName, "%s.%s_%s", pDb->name, pSchema->name, randStr);