diff --git a/diff.c b/diff.c
index 3aa695df62..17873f3d9e 100644
--- a/diff.c
+++ b/diff.c
@@ -2627,8 +2627,7 @@ static void fill_metainfo(struct strbuf *msg,
 			    (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
 				abbrev = 40;
 		}
-		strbuf_addf(msg, "%s%sindex %s..", set,
-			    line_prefix,
+		strbuf_addf(msg, "%s%sindex %s..", line_prefix, set,
 			    find_unique_abbrev(one->sha1, abbrev));
 		strbuf_addstr(msg, find_unique_abbrev(two->sha1, abbrev));
 		if (one->mode == two->mode)