diff --git a/src/input.c b/src/input.c
index 801454d..1509553 100644
--- a/src/input.c
+++ b/src/input.c
@@ -24,6 +24,7 @@
 #include "input.h"
 #include "scene.h"
 #include "vm.h"
+#include "xsystem4.h"
 #include "debugger.h"
 
 #ifndef M_PI