diff --git a/source/libs/function/test/udf1.c b/source/libs/function/test/udf1.c
index 1977c09e0f..7798a0bf3d 100644
--- a/source/libs/function/test/udf1.c
+++ b/source/libs/function/test/udf1.c
@@ -35,5 +35,6 @@ DLL_EXPORT int32_t udf1(SUdfDataBlock *block, SUdfColumn *resultCol) {
 #ifdef WINDOWS
   Sleep(1);
 #endif
+  resultData->numOfRows = block->numOfRows;
   return 0;
-}
\ No newline at end of file
+}