@@ -35,6 +35,9 @@ def validate_environment(self, *args, **kwargs):
 
         device_capability = torch.cuda.get_device_capability()
 
+        if device_capability[0] == 9:
+            raise ValueError("Loading Nunchaku checkpoints is not supported on Hopper NVIDIA GPUs.")
+
         has_nvfp4_config = (
             self.quantization_config.svdq_w4a4 is not None
             and self.quantization_config.svdq_w4a4["precision"] == "nvfp4"
 
@@ -0,0 +1 @@
+
@@ -0,0 +1,67 @@
+import unittest
+from unittest.mock import patch
+
+import torch
+
+from diffusers import NunchakuLiteQuantizationConfig
+from diffusers.quantizers.nunchaku import NunchakuLiteQuantizer
+
+
+def _compact_config(precision="nvfp4"):
+    return {
+        "svdq_w4a4": {
+            "precision": precision,
+            "group_size": 16 if precision == "nvfp4" else 64,
+            "rank": 4,
+            "targets": ["linear1"],
+        }
+    }
+
+
+class NunchakuLiteEnvironmentTests(unittest.TestCase):
+    def test_environment_rejects_hopper_cuda(self):
+        quantization_config = NunchakuLiteQuantizationConfig(compute_dtype=torch.bfloat16, **_compact_config("int4"))
+        quantizer = NunchakuLiteQuantizer(quantization_config)
+
+        with (
+            patch("diffusers.quantizers.nunchaku.nunchaku_quantizer.is_kernels_available", return_value=True),
+            patch("torch.cuda.is_available", return_value=True),
+            patch("torch.cuda.get_device_capability", return_value=(9, 0)),
+        ):
+            with self.assertRaisesRegex(ValueError, "not supported on Hopper NVIDIA GPUs"):
+                quantizer.validate_environment()
+
+    def test_nvfp4_environment_requires_blackwell_cuda(self):
+        quantization_config = NunchakuLiteQuantizationConfig(compute_dtype=torch.bfloat16, **_compact_config("nvfp4"))
+        quantizer = NunchakuLiteQuantizer(quantization_config)
+
+        with (
+            patch("diffusers.quantizers.nunchaku.nunchaku_quantizer.is_kernels_available", return_value=True),
+            patch("torch.cuda.is_available", return_value=True),
+            patch("torch.cuda.get_device_capability", return_value=(8, 9)),
+        ):
+            with self.assertRaisesRegex(ValueError, "Blackwell or newer NVIDIA GPU"):
+                quantizer.validate_environment()
+
+    def test_nvfp4_environment_allows_blackwell_cuda(self):
+        quantization_config = NunchakuLiteQuantizationConfig(compute_dtype=torch.bfloat16, **_compact_config("nvfp4"))
+        quantizer = NunchakuLiteQuantizer(quantization_config)
+
+        with (
+            patch("diffusers.quantizers.nunchaku.nunchaku_quantizer.is_kernels_available", return_value=True),
+            patch("torch.cuda.is_available", return_value=True),
+            patch("torch.cuda.get_device_capability", return_value=(10, 0)),
+        ):
+            quantizer.validate_environment()
+
+    def test_int4_environment_requires_turing_cuda(self):
+        quantization_config = NunchakuLiteQuantizationConfig(compute_dtype=torch.bfloat16, **_compact_config("int4"))
+        quantizer = NunchakuLiteQuantizer(quantization_config)
+
+        with (
+            patch("diffusers.quantizers.nunchaku.nunchaku_quantizer.is_kernels_available", return_value=True),
+            patch("torch.cuda.is_available", return_value=True),
+            patch("torch.cuda.get_device_capability", return_value=(7, 0)),
+        ):
+            with self.assertRaisesRegex(ValueError, "Turing or newer NVIDIA GPU"):
+                quantizer.validate_environment()