diff --git a/lisp/completion-preview.el b/lisp/completion-preview.el
index 1f9ba2c3d7a..17d9ca938a8 100644
--- a/lisp/completion-preview.el
+++ b/lisp/completion-preview.el
@@ -129,7 +129,7 @@ If this option is nil, these commands do not display any message."
 
 (defface completion-preview-exact
   ;; An exact match is also the longest common prefix of all matches.
-  '((t :underline "gray25" :inherit completion-preview-common))
+  '((t :underline "#00aa00" :inherit completion-preview-common))
   "Face for matches in the completion preview overlay."
   :version "30.1")