diff --git a/src/php/ext/grpc/php_grpc.c b/src/php/ext/grpc/php_grpc.c
index 1f9edfe..3e669ec 100644
--- a/src/php/ext/grpc/php_grpc.c
+++ b/src/php/ext/grpc/php_grpc.c
@@ -42,9 +42,9 @@
 #include "config.h"
 #endif
 
-#include "php.h"
-#include "php_ini.h"
-#include "ext/standard/info.h"
+#include <php.h>
+#include <php_ini.h>
+#include <ext/standard/info.h>
 #include "php_grpc.h"
 
 // ZEND_DECLARE_MODULE_GLOBALS(grpc)