diff --git a/vllm/model_executor/models/gemma2.py b/vllm/model_executor/models/gemma2.py
index 35e698fca410..7fb2e9948c06 100644
--- a/vllm/model_executor/models/gemma2.py
+++ b/vllm/model_executor/models/gemma2.py
@@ -145,8 +145,8 @@ def __init__(self,
         # reference:
         # https://github.com/huggingface/transformers/blob/54be2d7ae87e873482b984cc956e165ca4dc0ba3/src/transformers/models/gemma2/modeling_gemma2.py#L312 # noqa
         layer_idx = extract_layer_index(prefix)
-        use_sliding_window = (layer_idx % 2 == 0 and
-                              config.interleaved_sliding_window is not None)
+        use_sliding_window = (layer_idx % 2 == 0 and getattr(
+            config, "interleaved_sliding_window", None) is not None)
         sliding_window = config.interleaved_sliding_window if \
             use_sliding_window else None
         self.attn = Attention(self.num_heads,
diff --git a/vllm/model_executor/models/gemma3.py b/vllm/model_executor/models/gemma3.py
index 34957300ff9a..4e0d4f84ca6b 100644
--- a/vllm/model_executor/models/gemma3.py
+++ b/vllm/model_executor/models/gemma3.py
@@ -146,7 +146,9 @@ def __init__(self,
 
         # TODO(woosuk): Add reference to the original HF implementation.
         layer_idx = extract_layer_index(prefix)
-        self.is_sliding = bool((layer_idx + 1) % config.sliding_window_pattern)
+        self.is_sliding = (getattr(
+            config, "interleaved_sliding_window", None) is not None and bool(
+                (layer_idx + 1) % config.sliding_window_pattern))
         # Initialize the rotary embedding.
         if self.is_sliding:
             # Local attention. Override the values in config.json.
diff --git a/vllm/model_executor/models/gemma3_mm.py b/vllm/model_executor/models/gemma3_mm.py
index 6d3e6e389c47..65c177f8c5ad 100644
--- a/vllm/model_executor/models/gemma3_mm.py
+++ b/vllm/model_executor/models/gemma3_mm.py
@@ -478,7 +478,8 @@ def __init__(self, *, vllm_config: VllmConfig, prefix: str = ""):
         self.config = config
         self.quant_config = quant_config
         self.multimodal_config = multimodal_config
-        self.sliding_window = config.text_config.interleaved_sliding_window
+        self.sliding_window = getattr(config.text_config,
+                                      "interleaved_sliding_window", None)
 
         self.vision_tower = SiglipVisionModel(config.vision_config,
                                               quant_config,
@@ -680,13 +681,14 @@ def prepare_attn_masks(
             global_attn_mask = torch.where(img_mask == 2, 0, global_attn_mask)
             global_attn_masks.append(global_attn_mask)
 
-            # Create a local causal mask with sliding window (1024).
-            local_attn_mask = torch.ones_like(global_attn_mask)
-            local_attn_mask = torch.tril(local_attn_mask,
-                                         diagonal=-self.sliding_window)
-            local_attn_mask = torch.where(local_attn_mask == 0,
-                                          global_attn_mask, float("-inf"))
-            local_attn_masks.append(local_attn_mask)
+            if self.sliding_window is not None:
+                # Create a local causal mask with sliding window (1024).
+                local_attn_mask = torch.ones_like(global_attn_mask)
+                local_attn_mask = torch.tril(local_attn_mask,
+                                             diagonal=-self.sliding_window)
+                local_attn_mask = torch.where(local_attn_mask == 0,
+                                              global_attn_mask, float("-inf"))
+                local_attn_masks.append(local_attn_mask)
         kwargs["global_attn_masks"] = global_attn_masks
         kwargs["local_attn_masks"] = local_attn_masks
         return kwargs