diff --git a/src/util/inc/tcoding.h b/src/util/inc/tcoding.h
index ff34c1560703a820b296911065c42e224fefcc03..7a615a0ab8c94951a6f38bb98d073cb8b17af61a 100644
--- a/src/util/inc/tcoding.h
+++ b/src/util/inc/tcoding.h
@@ -355,8 +355,10 @@ static FORCE_INLINE void *taosDecodeString(void *buf, char **value) {
   uint64_t size = 0;
 
   buf = taosDecodeVariantU64(buf, &size);
-  *value = (char *)malloc((size_t)size + 1);
-  if (*value == NULL) return NULL;
+  if (*value == NULL) {
+    *value = (char *)malloc((size_t)size + 1);
+    if (*value == NULL) return NULL;
+  }
   memcpy(*value, buf, (size_t)size);
 
   (*value)[size] = '\0';