diff --git a/sgmse/backbones/ncsnpp_utils/op/__init__.py b/sgmse/backbones/ncsnpp_utils/op/__init__.py
index d0918d92285955855be89f00096b888ee5597ce3..857a9fc459361c342ff4f0e53085ab8712b6609e 100755
--- a/sgmse/backbones/ncsnpp_utils/op/__init__.py
+++ b/sgmse/backbones/ncsnpp_utils/op/__init__.py
@@ -1,2 +1 @@
-from .fused_act import FusedLeakyReLU, fused_leaky_relu
-from .upfirdn2d import upfirdn2d
+from .upfirdn2d import upfirdn2d
\ No newline at end of file
diff --git a/sgmse/backbones/ncsnpp_utils/op/upfirdn2d.py b/sgmse/backbones/ncsnpp_utils/op/upfirdn2d.py
index a4cf05dbcb2628fff56b0cb917c2941ce4a5f18b..0f4dc563d23a336fa129a925040d8ef7303b878b 100755
--- a/sgmse/backbones/ncsnpp_utils/op/upfirdn2d.py
+++ b/sgmse/backbones/ncsnpp_utils/op/upfirdn2d.py
@@ -7,14 +7,17 @@ from torch.utils.cpp_extension import load
 
 
 module_path = os.path.dirname(__file__)
-upfirdn2d_op = load(
-    "upfirdn2d",
-    sources=[
-        os.path.join(module_path, "upfirdn2d.cpp"),
-        os.path.join(module_path, "upfirdn2d_kernel.cu"),
-    ],
-)
 
+if torch.cuda.is_available():
+    upfirdn2d_op = load(
+        "upfirdn2d",
+        sources=[
+            os.path.join(module_path, "upfirdn2d.cpp"),
+            os.path.join(module_path, "upfirdn2d_kernel.cu"),
+        ],
+    )
+else:
+    upfirdn2d_op = None
 
 class UpFirDn2dBackward(Function):
     @staticmethod