1 files changed, 6 insertions, 1 deletions

diff --git a/sway/commands/titlebar_border_thickness.c b/sway/commands/titlebar_border_thickness.c
index 3c5e9ba1..7c27c163 100644
--- a/sway/commands/titlebar_border_thickness.c
+++ b/sway/commands/titlebar_border_thickness.c
@@ -21,7 +21,12 @@ struct cmd_results *cmd_titlebar_border_thickness(int argc, char **argv) {
 
         for (int i = 0; i < root->outputs->length; ++i) {
                 struct sway_output *output = root->outputs->items[i];
-                arrange_workspace(output_get_active_workspace(output));
+                struct sway_workspace *ws = output_get_active_workspace(output);
+                if (!sway_assert(ws, "Expected output to have a workspace")) {
+                        return cmd_results_new(CMD_FAILURE,
+                                        "Expected output to have a workspace");
+                }
+                arrange_workspace(ws);
                 output_damage_whole(output);
         }