diff --git a/builtin/last-modified.c b/builtin/last-modified.c
index 0df85be318..5366cedd0f 100644
--- a/builtin/last-modified.c
+++ b/builtin/last-modified.c
@@ -150,6 +150,11 @@ static int populate_paths_from_revs(struct last_modified *lm)
 			goto out;
 		}
 
+		if (!repo_peel_to_type(lm->rev.repo, obj->path, 0, obj->item, OBJ_COMMIT)) {
+			ret = error(_("revision argument is not a commit-ish"));
+			goto out;
+		}
+
 		diff_tree_oid(lm->rev.repo->hash_algo->empty_tree,
 			      &obj->item->oid, "", &diffopt);
 		diff_flush(&diffopt);
diff --git a/t/t8020-last-modified.sh b/t/t8020-last-modified.sh
index 1183ae667b..22635de447 100755
--- a/t/t8020-last-modified.sh
+++ b/t/t8020-last-modified.sh
@@ -8,6 +8,7 @@ test_expect_success 'setup' '
 	test_commit 1 file &&
 	mkdir a &&
 	test_commit 2 a/file &&
+	git tag -mA t2 2 &&
 	mkdir a/b &&
 	test_commit 3 a/b/file
 '
@@ -55,6 +56,13 @@ test_expect_success 'last-modified recursive' '
 	EOF
 '
 
+test_expect_success 'last-modified on annotated tag' '
+	check_last_modified t2 <<-\EOF
+	2 a
+	1 file
+	EOF
+'
+
 test_expect_success 'last-modified recursive with show-trees' '
 	check_last_modified -r -t <<-\EOF
 	3 a/b
@@ -235,4 +243,9 @@ test_expect_success 'last-modified complains about unknown arguments' '
 	grep "unknown last-modified argument: --foo" err
 '
 
+test_expect_success 'last-modified expects commit-ish' '
+	test_must_fail git last-modified HEAD^{tree} 2>err &&
+	grep "revision argument is not a commit-ish" err
+'
+
 test_done