diff --git a/src/transformers/integrations/awq.py b/src/transformers/integrations/awq.py
index dea74b2f7c3..8ef9a7ec96a 100644
--- a/src/transformers/integrations/awq.py
+++ b/src/transformers/integrations/awq.py
@@ -30,6 +30,13 @@ AWQ_FUSED_MAPPINGS = {
         "layernorm": ["input_layernorm", "post_attention_layernorm", "norm"],
         "use_alibi": False,
     },
+    "mixtral": {
+        "attention": ["q_proj", "k_proj", "v_proj", "o_proj"],
+        "mlp": ["w1", "w3", "w2"],
+        "layernorm": ["input_layernorm", "post_attention_layernorm", "norm"],
+        "use_alibi": False,
+        "rope_theta": 1000000.0,
+    },
     "llama": {
         "attention": ["q_proj", "k_proj", "v_proj", "o_proj"],
         "mlp": ["gate_proj", "up_proj", "down_proj"],
@@ -353,6 +360,8 @@ def _fuse_awq_attention_layers(model, module, modules_to_fuse, current_module_na
             previous_device,
             modules_to_fuse["max_seq_len"],
             use_alibi=modules_to_fuse["use_alibi"],
+            # The default value in autoawq is set to 10000.0
+            rope_theta=modules_to_fuse.get("rope_theta", 10000.0),
         )
 
         fused_attention_layer.is_hf_transformers = True
diff --git a/src/transformers/modeling_utils.py b/src/transformers/modeling_utils.py
index 2dc5a15a899..d7eec086bf9 100644
--- a/src/transformers/modeling_utils.py
+++ b/src/transformers/modeling_utils.py
@@ -3587,7 +3587,7 @@ class PreTrainedModel(nn.Module, ModuleUtilsMixin, GenerationMixin, PushToHubMix
             # a `modules_to_not_convert` attribute we need to manually set that attribute into the
             # passed `quantization_config`
             elif (
-                quantization_config.modules_to_not_convert is None
+                getattr(quantization_config, "modules_to_not_convert", None) is None
                 and "modules_to_not_convert" in config.quantization_config
             ):
                 quantization_config.modules_to_not_convert = config.quantization_config["modules_to_not_convert"]
diff --git a/tests/quantization/autoawq/test_awq.py b/tests/quantization/autoawq/test_awq.py
index 6ce7fca8fc6..be10eb8f918 100644
--- a/tests/quantization/autoawq/test_awq.py
+++ b/tests/quantization/autoawq/test_awq.py
@@ -254,6 +254,9 @@ class AwqFusedTest(unittest.TestCase):
     custom_mapping_model_id = "TheBloke/Yi-34B-AWQ"
     custom_model_revision = "f1b2cd1b7459ceecfdc1fac5bb8725f13707c589"
 
+    mixtral_model_name = "casperhansen/mixtral-instruct-awq"
+    mixtral_model_revision = "87dd4ec502dde74fb3a624835c776b000d190c3b"
+
     multi_modal_model_name = "ybelkada/llava-1.5-7b-hf-awq"
     multi_modal_model_code_revision = "ad108a50f5b9e681bdd7378409f57b7fa59a7442"
 
@@ -265,6 +268,7 @@ class AwqFusedTest(unittest.TestCase):
 
     EXPECTED_GENERATION = prompt + "\n\nThis is a classic puzzle that has been around for"
     EXPECTED_GENERATION_CUSTOM_MODEL = "HelloWorld.java:11)\r\n\tat org"
+    EXPECTED_GENERATION_MIXTRAL = prompt + " You're on the North Pole.\n\nThe"
 
     def tearDown(self):
         gc.collect()
@@ -300,6 +304,24 @@ class AwqFusedTest(unittest.TestCase):
         with self.assertRaises(ValueError), tempfile.TemporaryDirectory() as tmpdirname:
             model.save_pretrained(tmpdirname)
 
+    def test_fused_modules_to_not_convert(self):
+        """
+        Test if fused + modules to_not_covnert work as expected
+        """
+        model_id = "hf-internal-testing/Mixtral-tiny-AWQ"
+
+        quantization_config = AwqConfig(bits=4, fuse_max_seq_len=128, do_fuse=True)
+        model = AutoModelForCausalLM.from_pretrained(
+            model_id,
+            quantization_config=quantization_config,
+            low_cpu_mem_usage=True,
+        ).to(torch_device)
+
+        # Check if model has been correctly fused
+        self._check_fused_modules(model)
+        # Checks if the modules_to_not_convert (here gate layer) is a Linear
+        self.assertTrue(isinstance(model.model.layers[0].block_sparse_moe.gate, torch.nn.Linear))
+
     def test_generation_fused(self):
         """
         Test generation quality for fused models - single batch case
@@ -408,3 +430,24 @@ class AwqFusedTest(unittest.TestCase):
 
         outputs = model.generate(**inputs, max_new_tokens=12)
         self.assertEqual(tokenizer.decode(outputs[0], skip_special_tokens=True), self.EXPECTED_GENERATION_CUSTOM_MODEL)
+
+    @require_torch_multi_gpu
+    def test_generation_mixtral_fused(self):
+        """
+        Text generation test for Mixtral + AWQ + fused
+        """
+        quantization_config = AwqConfig(bits=4, fuse_max_seq_len=1024, do_fuse=True)
+        model = AutoModelForCausalLM.from_pretrained(
+            self.mixtral_model_name,
+            quantization_config=quantization_config,
+            device_map="auto",
+            revision=self.mixtral_model_revision,
+        )
+
+        tokenizer = AutoTokenizer.from_pretrained(self.mixtral_model_name)
+        tokenizer.pad_token = tokenizer.eos_token
+
+        inputs = tokenizer([self.prompt, self.prompt], return_tensors="pt", padding=True).to(torch_device)
+
+        outputs = model.generate(**inputs, max_new_tokens=12)
+        self.assertEqual(tokenizer.decode(outputs[0], skip_special_tokens=True), self.EXPECTED_GENERATION_MIXTRAL)