diff --git a/mercurial/filemerge.py b/mercurial/filemerge.py
--- a/mercurial/filemerge.py
+++ b/mercurial/filemerge.py
@@ -208,6 +208,8 @@ def _imerge(repo, mynode, orig, fcd, fco
     the partially merged file."""
     tool, toolpath, binary, symlink = toolconf
     if symlink:
+        repo.ui.warn(_('warning: internal:merge cannot merge symlinks '
+                       'for %s\n') % fcd.path())
         return False, 1
 
     r = _premerge(repo, toolconf, files)
diff --git a/tests/test-merge-tools.t b/tests/test-merge-tools.t
--- a/tests/test-merge-tools.t
+++ b/tests/test-merge-tools.t
@@ -843,6 +843,7 @@ internal merge cannot handle symlinks an
   $ hg commit -qm 'f is symlink'
   $ hg merge -r 2 --tool internal:merge
   merging f
+  warning: internal:merge cannot merge symlinks for f
   merging f incomplete! (edit conflicts, then use 'hg resolve --mark')
   0 files updated, 0 files merged, 0 files removed, 1 files unresolved
   use 'hg resolve' to retry unresolved file merges or 'hg update -C .' to abandon