diff --git a/i3bar/src/xcb.c b/i3bar/src/xcb.c
index ed578700..7f6379e1 100644
--- a/i3bar/src/xcb.c
+++ b/i3bar/src/xcb.c
@@ -329,6 +329,8 @@ void reconfig_windows() {
     uint32_t mask;
     uint32_t values[4];
 
+    xcb_generic_error_t *err;
+
     i3_output *walk;
     SLIST_FOREACH(walk, outputs, slist) {
         if (!walk->active) {