diff --git a/tests/model_executor/test_mistral_large_3_eagle.py b/tests/model_executor/test_mistral_large_3_eagle.py
new file mode 100644
index 00000000000..d8ef109af98
--- /dev/null
+++ b/tests/model_executor/test_mistral_large_3_eagle.py
@@ -0,0 +1,146 @@
+# SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
+
+from types import SimpleNamespace
+
+import pytest
+import torch
+import torch.nn as nn
+
+from vllm.config.compilation import CompilationMode
+from vllm.model_executor.models import deepseek_v2 as deepseek_mod
+from vllm.model_executor.models import mistral_large_3_eagle as eagle_mod
+
+
+class DummyPPGroup:
+    world_size = 1
+    is_first_rank = True
+    is_last_rank = True
+
+
+class DummyEmbedding(nn.Module):
+    def __init__(self, vocab_size, hidden_size, *args, **kwargs):
+        super().__init__()
+        self.hidden_size = hidden_size
+
+    def forward(self, input_ids):
+        return torch.zeros(
+            (*input_ids.shape, self.hidden_size),
+            dtype=torch.float32,
+            device=input_ids.device,
+        )
+
+
+class DummyLinear(nn.Module):
+    def __init__(self, in_features, out_features, *args, **kwargs):
+        super().__init__()
+        self.out_features = out_features
+
+    def forward(self, x):
+        return torch.zeros(
+            (*x.shape[:-1], self.out_features),
+            dtype=x.dtype,
+            device=x.device,
+        )
+
+
+class DummyNorm(nn.Module):
+    def __init__(self, *args, **kwargs):
+        super().__init__()
+
+    def forward(self, hidden_states, residual=None):
+        return hidden_states, residual
+
+
+class DummyDecoderLayer(nn.Module):
+    def __init__(self, *args, **kwargs):
+        super().__init__()
+
+    def forward(self, positions, hidden_states, residual, llama_4_scaling=None):
+        return hidden_states, residual
+
+
+def make_vllm_config(
+    *, model_type="mistral3", qk_nope_head_dim=128, qk_rope_head_dim=64
+):
+    hf_config = SimpleNamespace(
+        model_type=model_type,
+        first_k_dense_replace=0,
+        vocab_size=32000,
+        hidden_size=16,
+        num_hidden_layers=1,
+        rms_norm_eps=1e-5,
+        qk_nope_head_dim=qk_nope_head_dim,
+        qk_rope_head_dim=qk_rope_head_dim,
+    )
+
+    return SimpleNamespace(
+        model_config=SimpleNamespace(hf_config=hf_config),
+        quant_config=None,
+        parallel_config=SimpleNamespace(
+            eplb_config=SimpleNamespace(num_redundant_experts=0),
+        ),
+        scheduler_config=SimpleNamespace(max_num_batched_tokens=8),
+        cache_config=None,
+        compilation_config=SimpleNamespace(mode=CompilationMode.NONE),
+    )
+
+
+@pytest.fixture(autouse=True)
+def patch_heavy_modules(monkeypatch):
+    monkeypatch.setattr(eagle_mod, "get_pp_group", lambda: DummyPPGroup())
+    monkeypatch.setattr(deepseek_mod, "get_pp_group", lambda: DummyPPGroup())
+
+    monkeypatch.setattr(eagle_mod, "VocabParallelEmbedding", DummyEmbedding)
+    monkeypatch.setattr(eagle_mod, "RowParallelLinear", DummyLinear)
+    monkeypatch.setattr(eagle_mod, "RMSNorm", DummyNorm)
+    monkeypatch.setattr(eagle_mod, "DeepseekV2DecoderLayer", DummyDecoderLayer)
+
+
+@pytest.mark.cpu_test
+@pytest.mark.parametrize(
+    ("model_type", "qk_nope_head_dim", "qk_rope_head_dim", "expected_use_mha"),
+    [
+        # MLA-style config: should not use MHA.
+        ("mistral3", 128, 64, False),
+        # No MLA dims: should use MHA, matching DeepseekV2Model.__init__ logic.
+        ("mistral3", 0, 0, True),
+        # DeepSeek model type always uses MHA by the parent logic.
+        ("deepseek", 128, 64, True),
+    ],
+)
+def test_eagle_mistral_large3_initializes_deepseek_runtime_attrs(
+    model_type,
+    qk_nope_head_dim,
+    qk_rope_head_dim,
+    expected_use_mha,
+):
+    vllm_config = make_vllm_config(
+        model_type=model_type,
+        qk_nope_head_dim=qk_nope_head_dim,
+        qk_rope_head_dim=qk_rope_head_dim,
+    )
+
+    model = eagle_mod.EagleMistralLarge3Model(vllm_config=vllm_config)
+
+    assert model.aux_hidden_state_layers == ()
+    assert model.use_mha is expected_use_mha
+
+    # Add this if your fix also copies num_redundant_experts from
+    # DeepseekV2Model.__init__.
+    assert model.num_redundant_experts == 0
+
+
+@pytest.mark.cpu_test
+def test_eagle_mistral_large3_forward_reuses_deepseek_parent_forward():
+    vllm_config = make_vllm_config()
+    model = eagle_mod.EagleMistralLarge3Model(vllm_config=vllm_config)
+
+    input_ids = torch.tensor([[1, 2, 3]])
+    positions = torch.tensor([[0, 1, 2]])
+    hidden_states = torch.zeros((1, 3, 16))
+
+    output = model(input_ids, positions, hidden_states)
+
+    assert isinstance(output, torch.Tensor)
+    assert output.shape == hidden_states.shape
diff --git a/vllm/model_executor/models/mistral_large_3_eagle.py b/vllm/model_executor/models/mistral_large_3_eagle.py
index 3fcc048f9fa..bde5bc9451f 100644
--- a/vllm/model_executor/models/mistral_large_3_eagle.py
+++ b/vllm/model_executor/models/mistral_large_3_eagle.py
@@ -75,6 +75,16 @@ class EagleMistralLarge3Model(DeepseekV2Model):
         )
         self.norm = RMSNorm(config.hidden_size, eps=config.rms_norm_eps)
         self.aux_hidden_state_layers: tuple[int, ...] = ()
+
+        # Needed by load_weights
+        qk_nope_head_dim = getattr(config, "qk_nope_head_dim", 0)
+        qk_rope_head_dim = getattr(config, "qk_rope_head_dim", 0)
+        self.use_mha = config.model_type == "deepseek" or all(
+            dim == 0 for dim in (qk_nope_head_dim, qk_rope_head_dim)
+        )
+        self.num_redundant_experts = (
+            vllm_config.parallel_config.eplb_config.num_redundant_experts
+        )
         self.make_empty_intermediate_tensors = make_empty_intermediate_tensors_factory(
             ["hidden_states", "residual"], config.hidden_size
         )