diff --git a/window.c b/window.c
index c220215d..c949565b 100644
--- a/window.c
+++ b/window.c
@@ -22,6 +22,7 @@
 #include <errno.h>
 #include <fcntl.h>
 #include <fnmatch.h>
+#include <signal.h>
 #include <stdint.h>
 #include <stdlib.h>
 #include <string.h>