diff --git a/lisp/transient.el b/lisp/transient.el
index c9b24d62..80620cfa 100644
--- a/lisp/transient.el
+++ b/lisp/transient.el
@@ -3590,7 +3590,7 @@ have a history of their own.")
                              (button-get (1- (point)) 'command))
                         (transient--heading-at-point))))
       (erase-buffer)
-      (setq window-size-fixed 'height)
+      (setq window-size-fixed t)
       (when (bound-and-true-p tab-line-format)
         (setq tab-line-format nil))
       (setq header-line-format nil)