diff --git a/src/microhttpd/test_upgrade.c b/src/microhttpd/test_upgrade.c
index 6411adb3..2a0e21dd 100644
--- a/src/microhttpd/test_upgrade.c
+++ b/src/microhttpd/test_upgrade.c
@@ -27,13 +27,12 @@
  */
 
 #include "mhd_options.h"
-#include <stdlib.h>
-#include <string.h>
-#include <stdio.h>
-#include <pthread.h>
-#include <stdlib.h>
 #include <stddef.h>
 #include <stdint.h>
+#include <string.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <pthread.h>
 #include <errno.h>
 #ifndef WINDOWS
 #include <unistd.h>