diff --git a/customfuncs.c b/customfuncs.c
index 52ff39d..8f7bd42 100644
--- a/customfuncs.c
+++ b/customfuncs.c
@@ -1,4 +1,8 @@
 void togglefullscreen() {
+	if (selmon->sel == 0) {
+		return;
+	}
+
 	if (selmon->sel->isfullscreen) {
 		setfullscreen(selmon->sel, 0);
 	} else {