diff --git a/config.el b/config.el
index d6d8809..00257a2 100644
--- a/config.el
+++ b/config.el
@@ -145,7 +145,7 @@
   (setq magit-display-buffer-function #'magit-display-buffer-traditional))
 
 ;; Rainbow delimiters in all prog-mode buffers.
-(add-hook! prog-mode #'rainbow-delimiters-mode-enable)
+(add-hook 'prog-mode-hook #'rainbow-delimiters-mode-enable)
 
 ;; Make pyvenv more convenient by defaulting to the correct directory.
 (after! pyvenv