diff --git a/llms/mlx_lm/tuner/grpo_trainer.py b/llms/mlx_lm/tuner/grpo_trainer.py
index b7bdc7dc..b3619e0a 100644
--- a/llms/mlx_lm/tuner/grpo_trainer.py
+++ b/llms/mlx_lm/tuner/grpo_trainer.py
@@ -317,7 +317,9 @@ def grpo_loss(
     per_token_loss = -((policy_ratio * advantages.reshape(-1, 1) - beta * kl_div) * length_mask)
     
     # Average over tokens
-    loss = per_token_loss.sum().mean()
+    sequence_sums = per_token_loss.sum(axis=1)
+    sequence_lengths = length_mask.sum(axis=1)
+    loss = (sequence_sums / sequence_lengths).mean()
     
     # Calculate mean KL divergence for metrics
     mean_kl = ((kl_div * length_mask).sum(axis=1) / length_mask.sum(axis=1)).mean()
@@ -343,7 +345,7 @@ def grpo_loss(
     }
     mx.metal.clear_cache()
     
-    return loss, length_mask.sum(axis=1).sum(), metrics
+    return loss, sequence_lengths.sum(), metrics
 
 
 def iterate_grpo_batches(dataset, tokenizer, batch_size, max_seq_length, train=False):