diff --git a/demucs/pretrained.py b/demucs/pretrained.py
index 23cb8b0e..65851cb6 100644
--- a/demucs/pretrained.py
+++ b/demucs/pretrained.py
@@ -14,6 +14,7 @@
 
 from .hdemucs import HDemucs
 from .repo import RemoteRepo, LocalRepo, ModelOnlyRepo, BagOnlyRepo, AnyModelRepo, ModelLoadingError  # noqa
+from .states import _check_diffq
 
 logger = logging.getLogger(__name__)
 ROOT_URL = "https://dl.fbaipublicfiles.com/demucs/"
@@ -71,7 +72,13 @@ def get_model(name: str,
         model_repo = LocalRepo(repo)
         bag_repo = BagOnlyRepo(repo, model_repo)
     any_repo = AnyModelRepo(model_repo, bag_repo)
-    model = any_repo.get_model(name)
+    try:
+        model = any_repo.get_model(name)
+    except ImportError as exc:
+        if 'diffq' in exc.args[0]:
+            _check_diffq()
+        raise
+
     model.eval()
     return model
 
diff --git a/demucs/states.py b/demucs/states.py
index 48252c5e..361bb419 100644
--- a/demucs/states.py
+++ b/demucs/states.py
@@ -16,19 +16,32 @@
 import warnings
 
 from omegaconf import OmegaConf
-from diffq import DiffQuantizer, UniformQuantizer, restore_quantized_state
+from dora.log import fatal
 import torch
 
 
+def _check_diffq():
+    try:
+        import diffq  # noqa
+    except ImportError:
+        fatal('Trying to use DiffQ, but diffq is not installed.\n'
+              'On Windows run: python.exe -m pip install diffq \n'
+              'On Linux/Mac, run: python3 -m pip install diffq')
+
+
 def get_quantizer(model, args, optimizer=None):
     """Return the quantizer given the XP quantization args."""
     quantizer = None
     if args.diffq:
+        _check_diffq()
+        from diffq import DiffQuantizer
         quantizer = DiffQuantizer(
             model, min_size=args.min_size, group_size=args.group_size)
         if optimizer is not None:
             quantizer.setup_optimizer(optimizer)
     elif args.qat:
+        _check_diffq()
+        from diffq import UniformQuantizer
         quantizer = UniformQuantizer(
                 model, bits=args.qat, min_size=args.min_size)
     return quantizer
@@ -86,6 +99,8 @@ def set_state(model, state, quantizer=None):
         if quantizer is not None:
             quantizer.restore_quantized_state(model, state['quantized'])
         else:
+            _check_diffq()
+            from diffq import restore_quantized_state
             restore_quantized_state(model, state)
     else:
         model.load_state_dict(state)
diff --git a/docs/release.md b/docs/release.md
index 3870e165..005055d7 100644
--- a/docs/release.md
+++ b/docs/release.md
@@ -5,6 +5,8 @@
 Various improvements by @CarlGao4. Support for `segment` param inside of HTDemucs
 model.
 
+Made diffq an optional dependency, with an error message if not installed.
+
 ## V4.0.0, 7th of December 2022
 
 Adding hybrid transformer Demucs model.
diff --git a/hubconf.py b/hubconf.py
index 019b2e89..0cdb553e 100644
--- a/hubconf.py
+++ b/hubconf.py
@@ -4,7 +4,7 @@
 # This source code is licensed under the license found in the
 # LICENSE file in the root directory of this source tree.
 
-dependencies = ['dora-search', 'diffq', 'julius', 'lameenc', 'openunmix', 'pyyaml', 
+dependencies = ['dora-search', 'julius', 'lameenc', 'openunmix', 'pyyaml',
                 'torch', 'torchaudio', 'tqdm']
 
 from demucs.pretrained import get_model
diff --git a/requirements_minimal.txt b/requirements_minimal.txt
index f1ccb059..8c6f1e57 100644
--- a/requirements_minimal.txt
+++ b/requirements_minimal.txt
@@ -1,6 +1,5 @@
 # please make sure you have already a pytorch install that is cuda enabled!
 dora-search
-diffq>=0.2.1
 einops
 julius>=0.2.3
 lameenc>=1.2