diff --git a/xcompmgr.c b/xcompmgr.c
index a142cff..84f2703 100644
--- a/xcompmgr.c
+++ b/xcompmgr.c
@@ -36,6 +36,7 @@
 #include <sys/time.h>
 #include <time.h>
 #include <unistd.h>
+#include <getopt.h>
 #include <X11/Xlib.h>
 #include <X11/Xutil.h>
 #include <X11/Xatom.h>