diff --git a/tools/ismindex.c b/tools/ismindex.c
index ad1f3a848c..cf89f5c1e1 100644
--- a/tools/ismindex.c
+++ b/tools/ismindex.c
@@ -34,13 +34,9 @@
 
 #include <stdio.h>
 #include <string.h>
-#include <sys/stat.h>
-#ifdef _WIN32
-#include <direct.h>
-#define mkdir(a, b) _mkdir(a)
-#endif
 
 #include "libavformat/avformat.h"
+#include "libavformat/os_support.h"
 #include "libavutil/intreadwrite.h"
 #include "libavutil/mathematics.h"