diff --git a/src/axolotl/monkeypatch/llama_patch_multipack.py b/src/axolotl/monkeypatch/llama_patch_multipack.py
index 43b11d918..ad72af385 100644
--- a/src/axolotl/monkeypatch/llama_patch_multipack.py
+++ b/src/axolotl/monkeypatch/llama_patch_multipack.py
@@ -35,7 +35,7 @@ def hijack_llama_prepare_4d_mask():
         # return LlamaModel._prepare_4d_causal_attention_mask_with_cache_position(
         #     mask_2d_to_4d(attention_mask, dtype=dtype), **kwargs
         # )
-        return mask_2d_to_4d(attention_mask, dtype=dtype)
+        return mask_2d_to_4d(attention_mask, dtype=dtype).bool()
 
     LlamaModel._prepare_4d_causal_attention_mask_with_cache_position = (  # pylint: disable=protected-access
         llama_patched_prepare_4d_causal_attention_mask_with_cache_position