diff --git a/lisp/erc/erc-button.el b/lisp/erc/erc-button.el
index cb9af92ba12..4678e7b5609 100644
--- a/lisp/erc/erc-button.el
+++ b/lisp/erc/erc-button.el
@@ -130,7 +130,8 @@ longer than `erc-fill-column'."
     ("<URL: *\\([^<> ]+\\) *>" 0 t browse-url-button-open-url 1)
 ;;; ("(\\(\\([^~\n \t@][^\n \t@]*\\)@\\([a-zA-Z0-9.:-]+\\)\\)" 1 t finger 2 3)
     ;; emacs internal
-    ("[`]\\([a-zA-Z][-a-zA-Z_0-9]+\\)[']" 1 t erc-button-describe-symbol 1)
+    ("[`]\\([a-zA-Z][-a-zA-Z_0-9!*<=>+]+\\)[']"
+     1 t erc-button-describe-symbol 1)
     ;; pseudo links
     ("\\bInfo:[\"]\\([^\"]+\\)[\"]" 0 t Info-goto-node 1)
     ("\\b\\(Ward\\|Wiki\\|WardsWiki\\|TheWiki\\):\\([A-Z][a-z]+\\([A-Z][a-z]+\\)+\\)"