diff --git a/object-name.c b/object-name.c
index fdff4601b2..9750634ee7 100644
--- a/object-name.c
+++ b/object-name.c
@@ -361,6 +361,16 @@ static int show_ambiguous_object(const struct object_id *oid, void *data)
 		return 0;
 
 	type = oid_object_info(ds->repo, oid, NULL);
+
+	if (type < 0) {
+		strbuf_addstr(&desc, "[bad object]");
+		goto out;
+	}
+
+	assert(type == OBJ_TREE || type == OBJ_COMMIT ||
+	       type == OBJ_BLOB || type == OBJ_TAG);
+	strbuf_addstr(&desc, type_name(type));
+
 	if (type == OBJ_COMMIT) {
 		struct commit *commit = lookup_commit(ds->repo, oid);
 		if (commit) {
@@ -374,9 +384,9 @@ static int show_ambiguous_object(const struct object_id *oid, void *data)
 			strbuf_addf(&desc, " %s", tag->tag);
 	}
 
-	advise("  %s %s%s",
+out:
+	advise("  %s %s",
 	       repo_find_unique_abbrev(ds->repo, oid, DEFAULT_ABBREV),
-	       type_name(type) ? type_name(type) : "unknown type",
 	       desc.buf);
 
 	strbuf_release(&desc);
diff --git a/t/t1512-rev-parse-disambiguation.sh b/t/t1512-rev-parse-disambiguation.sh
index 010d9c1b8a..0282ada133 100755
--- a/t/t1512-rev-parse-disambiguation.sh
+++ b/t/t1512-rev-parse-disambiguation.sh
@@ -99,7 +99,7 @@ test_expect_success POSIXPERM 'ambigous zlib corrupt loose blob' '
 	error: unable to unpack cafe... header
 	error: inflate: data stream error (incorrect header check)
 	error: unable to unpack cafe... header
-	hint:   cafe... unknown type
+	hint:   cafe... [bad object]
 	hint:   cafe... blob
 	fatal: ambiguous argument '\''cafe...'\'': unknown revision or path not in the working tree.
 	Use '\''--'\'' to separate paths from revisions, like this: