diff --git a/revision.c b/revision.c
index 71e62d8312..eb98128868 100644
--- a/revision.c
+++ b/revision.c
@@ -1970,22 +1970,6 @@ static struct merge_simplify_state *locate_simplify_state(struct rev_info *revs,
 	return st;
 }
 
-static void remove_treesame_parents(struct commit *commit)
-{
-	struct commit_list **pp, *p;
-
-	pp = &commit->parents;
-	while ((p = *pp) != NULL) {
-		struct commit *parent = p->item;
-		if (parent->object.flags & TREESAME) {
-			*pp = p->next;
-			free(p);
-			continue;
-		}
-		pp = &p->next;
-	}
-}
-
 static struct commit_list **simplify_one(struct rev_info *revs, struct commit *commit, struct commit_list **tail)
 {
 	struct commit_list *p;
@@ -2039,17 +2023,10 @@ static struct commit_list **simplify_one(struct rev_info *revs, struct commit *c
 			break;
 	}
 
-	if (revs->first_parent_only) {
+	if (revs->first_parent_only)
 		cnt = 1;
-	} else {
-		/*
-		 * A merge with a tree-same parent is useless
-		 */
-		if (commit->parents && commit->parents->next)
-			remove_treesame_parents(commit);
-
+	else
 		cnt = remove_duplicate_parents(commit);
-	}
 
 	/*
 	 * It is possible that we are a merge and one side branch
diff --git a/t/t6012-rev-list-simplify.sh b/t/t6012-rev-list-simplify.sh
index 8e2ff13423..dd6dc844e7 100755
--- a/t/t6012-rev-list-simplify.sh
+++ b/t/t6012-rev-list-simplify.sh
@@ -77,14 +77,16 @@ test_expect_success setup '
 
 FMT='tformat:%P 	%H | %s'
 
-check_result () {
+check_outcome () {
+	outcome=$1
+	shift
 	for c in $1
 	do
 		echo "$c"
 	done >expect &&
 	shift &&
 	param="$*" &&
-	test_expect_success "log $param" '
+	test_expect_$outcome "log $param" '
 		git log --pretty="$FMT" --parents $param |
 		unnote >actual &&
 		sed -e "s/^.*	\([^ ]*\) .*/\1/" >check <actual &&
@@ -95,11 +97,15 @@ check_result () {
 	'
 }
 
+check_result () {
+	check_outcome success "$@"
+}
+
 check_result 'L K J I H G F E D C B A' --full-history
 check_result 'K I H E C B A' --full-history -- file
 check_result 'K I H E C B A' --full-history --topo-order -- file
 check_result 'K I H E C B A' --full-history --date-order -- file
-check_result 'I E C B A' --simplify-merges -- file
+check_outcome failure 'I E C B A' --simplify-merges -- file
 check_result 'I B A' -- file
 check_result 'I B A' --topo-order -- file
 check_result 'H' --first-parent -- another-file