diff --git a/command.c b/command.c
index ba23b7e005..e666aee1d2 100644
--- a/command.c
+++ b/command.c
@@ -61,6 +61,7 @@
 
 #include "mp_core.h"
 #include "mp_fifo.h"
+#include "libavutil/avstring.h"
 
 #define ROUND(x) ((int)((x)<0 ? (x)-0.5 : (x)+0.5))