diff --git a/pkmn/index.test.ts b/pkmn/index.test.ts
index 604d6d640..1663eff22 100644
--- a/pkmn/index.test.ts
+++ b/pkmn/index.test.ts
@@ -134,6 +134,7 @@ describe('Smogon', () => {
     expect(Smogon.format(gen(2), 'Snorlax')).toBe('gen2ou');
     expect(Smogon.format(gen(3), 'Dragonair')).toBe('gen3pu');
     expect(Smogon.format(gen(6), 'Vanilluxe')).toBe('gen6zu');
+    expect(Smogon.format(gen(1), 'Arbok')).toBe('gen1pu');
   });
 
   test('name', () => {
diff --git a/pkmn/index.ts b/pkmn/index.ts
index 12df310e4..6430db2c2 100644
--- a/pkmn/index.ts
+++ b/pkmn/index.ts
@@ -161,14 +161,14 @@ const PREFIXES = ['Pichu', 'Basculin', 'Keldeo', 'Genesect', 'Vivillon', 'Magear
 const SUFFIXES = ['-Antique', '-Totem'];
 
 // Conversion between a Pokémon's Tier and a format suffix.
-const FORMATS: {[key in Exclude<Tier.Singles | 'ZU' | Tier.Other, 'NFE'>]: string} = {
+const FORMATS: {[key in Exclude<Tier.Singles | 'ZU' | 'ZUBL' | Tier.Other, 'NFE'>]: string} = {
   AG: 'anythinggoes',
   Uber: 'ubers', '(Uber)': 'ubers',
   OU: 'ou', '(OU)': 'ou', 'UUBL': 'ou',
   UU: 'uu', 'RUBL': 'uu',
   RU: 'ru', 'NUBL': 'ru',
   NU: 'nu', '(NU)': 'nu', 'PUBL': 'nu',
-  PU: 'pu', '(PU)': 'pu',
+  PU: 'pu', '(PU)': 'pu', 'ZUBL': 'pu',
   ZU: 'zu',
   LC: 'lc',
   Unreleased: 'anythinggoes',
diff --git a/pkmn/package.json b/pkmn/package.json
index 547ed378c..14ee379be 100644
--- a/pkmn/package.json
+++ b/pkmn/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@pkmn/smogon",
-  "version": "0.5.12",
+  "version": "0.5.13",
   "description": "A rich client for processed and aggregated Smogon analysis and moveset information",
   "homepage": "https://data.pkmn.cc/",
   "repository": "github:pkmn/smogon",