--- a/mercurial/commands.py	Wed Apr 04 15:06:32 2018 -0700
+++ b/mercurial/commands.py	Wed Apr 04 15:08:26 2018 -0700
@@ -2648,7 +2648,8 @@
         heads = [repo[h] for h in heads]
 
     if branchrevs:
-        branches = set(repo[br].branch() for br in branchrevs)
+        branches = set(repo[r].branch()
+                       for r in scmutil.revrange(repo, branchrevs))
         heads = [h for h in heads if h.branch() in branches]
 
     if opts.get('active') and branchrevs: