diff --git a/gitimerge.py b/gitimerge.py
index fe99c30..b4bc632 100644
--- a/gitimerge.py
+++ b/gitimerge.py
@@ -2391,7 +2391,7 @@ def _check_no_merges(git, commits):
             ]
         if multiparent_commits:
             raise Failure(
-                'The following commits on the to-be-merged branch are merge commits:\n'
+                'The following commits on the to-be-rebased branch are merge commits:\n'
                 '    %s\n'
                 '--goal=\'rebase\' is not yet supported for branches that include merges.\n'
                 % ('\n    '.join(multiparent_commits),)