diff --git a/dwm.c b/dwm.c
index 242909e..c58300f 100644
--- a/dwm.c
+++ b/dwm.c
@@ -990,7 +990,7 @@ focusstack(const Arg *arg)
 	int i = stackpos(arg);
 	Client *c, *p;
 
-	if (i < 0 || selmon->sel->isfullscreen)
+	if (i < 0 || !selmon->sel || selmon->sel->isfullscreen)
 		return;
 
 	for(p = NULL, c = selmon->clients; c && (i || !ISVISIBLE(c));
@@ -1404,7 +1404,7 @@ pushstack(const Arg *arg) {
 	int i = stackpos(arg);
 	Client *sel = selmon->sel, *c, *p;
 
-	if(i < 0)
+	if(i < 0 || !sel)
 		return;
 	else if(i == 0) {
 		detach(sel);