diff --git a/src/system/detail/src/vnodeFile.c b/src/system/detail/src/vnodeFile.c
index 7597659e5308a077dd18054a323ae8ff44a24318..b69320a03c9d586dd17e668ad50f0a763eff0dd4 100644
--- a/src/system/detail/src/vnodeFile.c
+++ b/src/system/detail/src/vnodeFile.c
@@ -1311,6 +1311,7 @@ int vnodeWriteBlockToFile(SMeterObj *pObj, SCompBlock *pCompBlock, SData *data[]
   pCompBlock->keyFirst = *((TSKEY *)(data[0]->data));  // hack way to get the key
   pCompBlock->keyLast = *((TSKEY *)(data[0]->data + (points - 1) * pObj->schema[0].bytes));
   pCompBlock->sversion = pObj->sversion;
+  assert(pCompBlock->keyFirst <= pCompBlock->keyLast);
 
   return 0;
 }