diff --git a/unsloth/models/llama.py b/unsloth/models/llama.py
index 38b8f55d11..06b78d77c5 100644
--- a/unsloth/models/llama.py
+++ b/unsloth/models/llama.py
@@ -460,7 +460,7 @@ def LlamaModel_fast_forward(
             (batch_size, seq_length),
             inputs_embeds,
             past_key_values_length,
-            sliding_window = getattr(self.config, "sliding_window"),
+            sliding_window = getattr(self.config, "sliding_window", None),
         )
     pass
 
diff --git a/unsloth/models/mistral.py b/unsloth/models/mistral.py
index eb9d10513f..2c85129010 100644
--- a/unsloth/models/mistral.py
+++ b/unsloth/models/mistral.py
@@ -131,7 +131,7 @@ def MistralAttention_fast_forward(
         Q = Q.transpose(1, 2)
         K = K.transpose(1, 2)
         V = V.transpose(1, 2)
-        sw = getattr(self.config, "sliding_window")
+        sw = getattr(self.config, "sliding_window", None)
         sw = q_len if sw is None else sw
         window = (-1, -1) if (q_len <= sw) else (sw, sw)
         A = flash_attn_func(Q, K, V, causal = True, window_size = window)
@@ -175,7 +175,7 @@ def MistralForCausalLM_fast_forward(
 
     if causal_mask is None:
         bsz, q_len = input_ids.shape
-        sliding_window = getattr(self.config, "sliding_window")
+        sliding_window = getattr(self.config, "sliding_window", None)
         if sliding_window is None or sliding_window <= 0:
             causal_mask = xformers.attn_bias.LowerTriangularMask()
         elif q_len <= sliding_window: