diff --git a/player/core.h b/player/core.h
index 7b3e47d8d2..885c2d2052 100644
--- a/player/core.h
+++ b/player/core.h
@@ -19,6 +19,7 @@
 #define MPLAYER_MP_CORE_H
 
 #include <stdbool.h>
+#include <pthread.h>
 
 #include "libmpv/client.h"