diff --git a/control.c b/control.c
index e4efb01f..30536183 100644
--- a/control.c
+++ b/control.c
@@ -208,10 +208,12 @@ control_free_sub(struct control_state *cs, struct control_sub *csub)
 
 	RB_FOREACH_SAFE(csp, control_sub_panes, &csub->panes, csp1) {
 		RB_REMOVE(control_sub_panes, &csub->panes, csp);
+		free(csp->last);
 		free(csp);
 	}
 	RB_FOREACH_SAFE(csw, control_sub_windows, &csub->windows, csw1) {
 		RB_REMOVE(control_sub_windows, &csub->windows, csw);
+		free(csw->last);
 		free(csw);
 	}
 	free(csub->last);