diff --git a/libavformat/tls_schannel.c b/libavformat/tls_schannel.c
index c76f8a9aa6..85c01a0d64 100644
--- a/libavformat/tls_schannel.c
+++ b/libavformat/tls_schannel.c
@@ -28,6 +28,7 @@
 #include "tls.h"
 
 #define SECURITY_WIN32
+#include <windows.h>
 #include <security.h>
 #include <schnlsp.h>