diff --git a/aos/ipc_lib/index.cc b/aos/ipc_lib/index.cc
index ed58806..4701f51 100644
--- a/aos/ipc_lib/index.cc
+++ b/aos/ipc_lib/index.cc
@@ -1,7 +1,7 @@
 #include "aos/ipc_lib/index.h"
 
-#include <string>
 #include <sstream>
+#include <string>
 
 namespace aos {
 namespace ipc_lib {