diff --git a/src/layout.c b/src/layout.c
index ce81e06..877e04a 100644
--- a/src/layout.c
+++ b/src/layout.c
@@ -39,6 +39,9 @@ arrange(int screen)
 {
      Client *c;
 
+     if(screen < 0 || screen > screen_count())
+          screen = screen_get_sel();
+
      for(c = clients; c; c = c->next)
           if(c->screen == screen)
           {
diff --git a/src/wmfs.c b/src/wmfs.c
index ec59a72..d9b87f5 100644
--- a/src/wmfs.c
+++ b/src/wmfs.c
@@ -222,7 +222,7 @@ scan(void)
 
                     if(tag != -1)
                          c->tag = tag;
-                    if(screen != -1)
+                    if(screen != -1 && screen <= screen_count() - 1)
                          c->screen = screen;
 
                     client_update_attributes(c);