diff --git a/cmake/checks/ffmpeg_test.cpp b/cmake/checks/ffmpeg_test.cpp
index 7b49c38c7a..81c755632f 100644
--- a/cmake/checks/ffmpeg_test.cpp
+++ b/cmake/checks/ffmpeg_test.cpp
@@ -1,3 +1,5 @@
+#define __STDC_CONSTANT_MACROS
+
 #include <stdlib.h>
 
 extern "C" {