diff --git a/builtin/describe.c b/builtin/describe.c
index 06e413d937..f7bea3c8c5 100644
--- a/builtin/describe.c
+++ b/builtin/describe.c
@@ -518,10 +518,16 @@ static void describe_blob(const struct object_id *oid, struct strbuf *dst)
 {
 	struct rev_info revs;
 	struct strvec args = STRVEC_INIT;
+	struct object_id head_oid;
 	struct process_commit_data pcd = { *null_oid(the_hash_algo), oid, dst, &revs};
 
+	if (repo_get_oid(the_repository, "HEAD", &head_oid))
+		die(_("cannot search for blob '%s' on an unborn branch"),
+		    oid_to_hex(oid));
+
 	strvec_pushl(&args, "internal: The first arg is not parsed",
-		     "--objects", "--in-commit-order", "--reverse", "HEAD",
+		     "--objects", "--in-commit-order", "--reverse",
+		     oid_to_hex(&head_oid),
 		     NULL);
 
 	repo_init_revisions(the_repository, &revs, NULL);
diff --git a/t/t6120-describe.sh b/t/t6120-describe.sh
index 470631d17d..feec57bcbc 100755
--- a/t/t6120-describe.sh
+++ b/t/t6120-describe.sh
@@ -415,6 +415,14 @@ test_expect_success 'describe an unreachable blob' '
 	test_grep "blob .$blob. not reachable from HEAD" actual
 '
 
+test_expect_success 'describe blob on an unborn branch' '
+	oldbranch=$(git symbolic-ref HEAD) &&
+	test_when_finished "git symbolic-ref HEAD $oldbranch" &&
+	git symbolic-ref HEAD refs/heads/does-not-exist &&
+	test_must_fail git describe test-blob 2>actual &&
+	test_grep "cannot search .* on an unborn branch" actual
+'
+
 test_expect_success ULIMIT_STACK_SIZE 'name-rev works in a deep repo' '
 	i=1 &&
 	while test $i -lt 8000