diff --git a/.emacs.d/lisp/init-sly-narrow.el b/.emacs.d/lisp/init-sly-narrow.el
index d9f9999a..e9462b08 100644
--- a/.emacs.d/lisp/init-sly-narrow.el
+++ b/.emacs.d/lisp/init-sly-narrow.el
@@ -36,6 +36,7 @@
    (ambrevar/sly-prompt-begin-position)
    (ambrevar/sly-output-end-position)))
 
-(define-key sly-mrepl-mode-map (kbd "C-x n d") 'ambrevar/sly-narrow-to-prompt)
+(with-eval-after-load 'sly-mrepl
+  (define-key sly-mrepl-mode-map (kbd "C-x n d") 'ambrevar/sly-narrow-to-prompt))
 
 (provive 'init-sly-narrow)