diff --git a/src/connector/odbc/src/todbc.c b/src/connector/odbc/src/todbc.c
index 953999c434dd3c75670ae06f6b0d7291702d77df..7de46a444e1c3fee25d43266d6c9c37f3dfce500 100644
--- a/src/connector/odbc/src/todbc.c
+++ b/src/connector/odbc/src/todbc.c
@@ -16,6 +16,7 @@
 // #define _BSD_SOURCE
 #define _XOPEN_SOURCE
 #define _DEFAULT_SOURCE
+#define _GNU_SOURCE
 
 #include "taos.h"