diff --git a/src/diffusers/quantizers/nunchaku/nunchaku_quantizer.py b/src/diffusers/quantizers/nunchaku/nunchaku_quantizer.py
index 113d9a4ba1..c61ac26928 100644
--- a/src/diffusers/quantizers/nunchaku/nunchaku_quantizer.py
+++ b/src/diffusers/quantizers/nunchaku/nunchaku_quantizer.py
@@ -164,6 +164,11 @@ class NunchakuQuantizer(DiffusersQuantizer):
             self.modules_to_not_convert = [self.modules_to_not_convert]
 
         self.modules_to_not_convert.extend(keep_in_fp32_modules)
+        # Purge `None`.
+        # Unlike `transformers`, we don't know if we should always keep certain modules in FP32
+        # in case of diffusion transformer models. For language models and others alike, `lm_head`
+        # and tied modules are usually kept in FP32.
+        self.modules_to_not_convert = [module for module in self.modules_to_not_convert if module is not None]
 
         model = replace_with_nunchaku_linear(
             model,
diff --git a/src/diffusers/quantizers/nunchaku/utils.py b/src/diffusers/quantizers/nunchaku/utils.py
index af36d7e638..b8b015e6ee 100644
--- a/src/diffusers/quantizers/nunchaku/utils.py
+++ b/src/diffusers/quantizers/nunchaku/utils.py
@@ -5,7 +5,6 @@ from ...utils import is_accelerate_available, is_nunchaku_available, logging
 
 if is_accelerate_available():
     from accelerate import init_empty_weights
-    
 
 
 logger = logging.get_logger(__name__)
@@ -40,7 +39,7 @@ def _replace_with_nunchaku_linear(
                             out_features,
                             rank=quantization_config.rank,
                             bias=module.bias is not None,
-                            dtype=model.dtype,
+                            torch_dtype=module.weight.dtype,
                         )
                         has_been_replaced = True
                     # Store the module class in case we need to transpose the weight later
@@ -50,6 +49,7 @@ def _replace_with_nunchaku_linear(
         if len(list(module.children())) > 0:
             _, has_been_replaced = _replace_with_nunchaku_linear(
                 module,
+                svdq_linear_cls,
                 modules_to_not_convert,
                 current_key_name,
                 quantization_config,
@@ -64,7 +64,9 @@ def replace_with_nunchaku_linear(model, modules_to_not_convert=None, current_key
     if is_nunchaku_available():
         from nunchaku.models.linear import SVDQW4A4Linear
 
-    model, _ = _replace_with_nunchaku_linear(model, SVDQW4A4Linear, modules_to_not_convert, current_key_name, quantization_config)
+    model, _ = _replace_with_nunchaku_linear(
+        model, SVDQW4A4Linear, modules_to_not_convert, current_key_name, quantization_config
+    )
 
     has_been_replaced = any(
         isinstance(replaced_module, SVDQW4A4Linear) for _, replaced_module in model.named_modules()
diff --git a/src/diffusers/quantizers/quantization_config.py b/src/diffusers/quantizers/quantization_config.py
index 057a5aec71..acde80879a 100644
--- a/src/diffusers/quantizers/quantization_config.py
+++ b/src/diffusers/quantizers/quantization_config.py
@@ -750,6 +750,7 @@ class NunchakuConfig(QuantizationConfigMixin):
     ):
         self.quant_method = QuantizationMethod.NUNCHAKU
         self.precision = precision
+        self.rank = rank
         self.group_size = self.group_size_map[precision]
         self.modules_to_not_convert = modules_to_not_convert
 
@@ -763,6 +764,8 @@ class NunchakuConfig(QuantizationConfigMixin):
         if self.precision not in accpeted_precision:
             raise ValueError(f"Only supported precision in {accpeted_precision} but found {self.precision}")
 
+        # TODO: should there be a check for rank?
+
     # Copied from diffusers.quantizers.bitsandbytes.quantization_config.BitsandBytesConfig.to_diff_dict with BitsandBytesConfig->NunchakuConfig
     def to_diff_dict(self) -> Dict[str, Any]:
         """