diff --git a/docs/registry_test.go b/docs/registry_test.go
index ebfb99b4c..c072da41c 100644
--- a/docs/registry_test.go
+++ b/docs/registry_test.go
@@ -206,4 +206,8 @@ func TestValidRepositoryName(t *testing.T) {
 		t.Log("Repository name should be invalid")
 		t.Fail()
 	}
+	if err := validateRepositoryName("docker///docker"); err == nil {
+		t.Log("Repository name should be invalid")
+		t.Fail()
+	}
 }