diff --git a/ewmh.c b/ewmh.c
index 17bb886b..54607342 100644
--- a/ewmh.c
+++ b/ewmh.c
@@ -175,7 +175,8 @@ ewmh_update_net_current_desktop(int phys_screen)
     uint32_t count = 0;
     tag_t **curtags = tags_get_current(phys_screen);
 
-    for(count = 0; tags->tab[count] != curtags[0]; count++);
+    while(count < (uint32_t) tags->len && tags->tab[count] != curtags[0])
+        count++;
 
     xcb_change_property(globalconf.connection, XCB_PROP_MODE_REPLACE,
                         xutil_screen_get(globalconf.connection, phys_screen)->root,