diff --git a/source/client/src/TMQConnector.c b/source/client/src/TMQConnector.c
index b000dd6a32..17d3a212c4 100644
--- a/source/client/src/TMQConnector.c
+++ b/source/client/src/TMQConnector.c
@@ -322,7 +322,7 @@ JNIEXPORT jint JNICALL Java_com_taosdata_jdbc_tmq_TMQConnector_fetchRawBlockImp(
   (*env)->CallVoidMethod(env, rowobj, g_blockdataSetNumOfRowsFp, (jint)numOfRows);
   (*env)->CallVoidMethod(env, rowobj, g_blockdataSetNumOfColsFp, (jint)numOfFields);
 
-  int32_t len = *(int32_t *)(data + 4);
+  int32_t len = *(int32_t *)(((char *)data) + 4);
   (*env)->CallVoidMethod(env, rowobj, g_blockdataSetByteArrayFp, jniFromNCharToByteArray(env, (char *)data, len));
   return JNI_SUCCESS;
 }
diff --git a/source/client/src/TSDBJNIConnector.c b/source/client/src/TSDBJNIConnector.c
index e027066d10..b5a6ebadee 100644
--- a/source/client/src/TSDBJNIConnector.c
+++ b/source/client/src/TSDBJNIConnector.c
@@ -592,7 +592,7 @@ JNIEXPORT jint JNICALL Java_com_taosdata_jdbc_TSDBJNIConnector_fetchBlockImp(JNI
   (*env)->CallVoidMethod(env, rowobj, g_blockdataSetNumOfRowsFp, (jint)numOfRows);
   (*env)->CallVoidMethod(env, rowobj, g_blockdataSetNumOfColsFp, (jint)numOfFields);
 
-  int32_t len = *(int32_t *)(data + 4);
+  int32_t len = *(int32_t *)(((char *)data) + 4);
   (*env)->CallVoidMethod(env, rowobj, g_blockdataSetByteArrayFp, jniFromNCharToByteArray(env, (char *)data, len));
 
   return JNI_SUCCESS;