diff --git a/mercurial/help/config.txt b/mercurial/help/config.txt
index 9482d4a87d..46b2e3649e 100644
--- a/mercurial/help/config.txt
+++ b/mercurial/help/config.txt
@@ -982,7 +982,8 @@ Supported arguments:
   launching external tool.  Options are ``true``, ``false``, ``keep`` or
   ``keep-merge3``. The ``keep`` option will leave markers in the file if the
   premerge fails. The ``keep-merge3`` will do the same but include information
-  about the base of the merge in the marker (see internal:merge3).
+  about the base of the merge in the marker (see internal :merge3 in
+  :hg:`help merge-tools`).
   Default: True
 
 ``binary``