diff --git a/README.md b/README.md
index 6425f431ab..1ea8b9d86d 100644
--- a/README.md
+++ b/README.md
@@ -138,11 +138,10 @@ model = AutoModelForCausalLMWithValueHead.from_pretrained('gpt2')
 model_ref = create_reference_model(model)
 
 tokenizer = AutoTokenizer.from_pretrained('gpt2')
+tokenizer.pad_token = tokenizer.eos_token
 
 # initialize trainer
-ppo_config = PPOConfig(
-    batch_size=1,
-)
+ppo_config = PPOConfig(batch_size=1, mini_batch_size=1)
 
 # encode a query
 query_txt = "This morning I went to the "