diff --git a/src/query/src/qExtbuffer.c b/src/query/src/qExtbuffer.c
index a73f38528266bfa70790414a2963eb0a8290d7b9..73b5b81e52628a4bd151869487150d97a09b8155 100644
--- a/src/query/src/qExtbuffer.c
+++ b/src/query/src/qExtbuffer.c
@@ -266,6 +266,7 @@ int32_t tExtMemBufferFlush(tExtMemBuffer *pMemBuffer) {
     size_t retVal = fwrite((char *)&(first->item), pMemBuffer->pageSize, 1, pMemBuffer->file);
     if (retVal <= 0) {  // failed to write to buffer, may be not enough space
       ret = TAOS_SYSTEM_ERROR(errno);
+      pMemBuffer->pHead = first;
       return ret;
     }