diff --git a/revision.c b/revision.c
index 8eb7cb9bbc..526bcf3fb5 100644
--- a/revision.c
+++ b/revision.c
@@ -1153,12 +1153,18 @@ static int process_parents(struct rev_info *revs, struct commit *commit,
 			if (p)
 				p->object.flags |= UNINTERESTING |
 						   CHILD_VISITED;
-			if (repo_parse_commit_gently(revs->repo, p, 1) < 0)
+			if (repo_parse_commit_gently(revs->repo, p, 1) < 0) {
+				if (revs->exclude_first_parent_only)
+					break;
 				continue;
+			}
 			if (p->parents)
 				mark_parents_uninteresting(revs, p);
-			if (p->object.flags & SEEN)
+			if (p->object.flags & SEEN) {
+				if (revs->exclude_first_parent_only)
+					break;
 				continue;
+			}
 			p->object.flags |= (SEEN | NOT_USER_GIVEN);
 			if (queue)
 				prio_queue_put(queue, p);
diff --git a/t/t6012-rev-list-simplify.sh b/t/t6012-rev-list-simplify.sh
index 4cecb6224c..2284bbba12 100755
--- a/t/t6012-rev-list-simplify.sh
+++ b/t/t6012-rev-list-simplify.sh
@@ -285,4 +285,22 @@ test_expect_success 'log --graph --simplify-merges --show-pulls' '
 	test_cmp expect actual
 '
 
+test_expect_success 'exclude-first-parent-only with parent already seen' '
+	git checkout --orphan test-seen &&
+	git rm -rf . &&
+	test_commit r1 &&
+	git checkout -b branch-f &&
+	test_commit f &&
+	git checkout test-seen &&
+	git merge --no-ff --no-edit -m r2 branch-f &&
+	git tag r2 &&
+
+	git rev-list --exclude-first-parent-only f ^r2 >actual &&
+	git rev-parse f >expect &&
+	test_cmp expect actual &&
+
+	git rev-list --exclude-first-parent-only f r1 ^r2 >actual2 &&
+	test_cmp expect actual2
+'
+
 test_done