diff --git a/candle-core/src/custom_op.rs b/candle-core/src/custom_op.rs
index c0d97d670..3a85dba9f 100644
--- a/candle-core/src/custom_op.rs
+++ b/candle-core/src/custom_op.rs
@@ -375,110 +375,3 @@ impl Tensor {
         )
     }
 }
-
-pub struct UgIOp1 {
-    name: &'static str,
-    #[cfg(feature = "cuda")]
-    func: cudarc::driver::CudaFunction,
-    #[cfg(feature = "metal")]
-    func: metal::ComputePipelineState,
-}
-
-impl UgIOp1 {
-    #[allow(unused)]
-    pub fn new(
-        name: &'static str,
-        kernel: ug::lang::ssa::Kernel,
-        device: &crate::Device,
-    ) -> Result<Self> {
-        #[cfg(feature = "cuda")]
-        {
-            let device = device.as_cuda_device()?;
-            let func = device.compile(name, kernel)?;
-            Ok(Self { name, func })
-        }
-        #[cfg(feature = "metal")]
-        {
-            let device = device.as_metal_device()?;
-            let func = device.compile(name, kernel)?;
-            Ok(Self { name, func })
-        }
-        #[cfg(not(any(feature = "cuda", feature = "metal")))]
-        {
-            Ok(Self { name })
-        }
-    }
-}
-
-impl InplaceOp1 for UgIOp1 {
-    fn name(&self) -> &'static str {
-        self.name
-    }
-
-    fn cpu_fwd(&self, _: &mut CpuStorage, _: &Layout) -> Result<()> {
-        crate::bail!("ug ops are only supported on metal/cuda at the moment")
-    }
-
-    #[cfg(feature = "metal")]
-    fn metal_fwd(&self, sto: &mut MetalStorage, layout: &Layout) -> Result<()> {
-        use crate::backend::BackendStorage;
-        use candle_metal_kernels::utils::EncoderProvider;
-
-        let elem_count = layout.shape().elem_count();
-        if sto.dtype() != crate::DType::F32 {
-            // TODO: support more dtypes.
-            crate::bail!("input is not a f32 tensor")
-        }
-        let device = sto.device();
-        println!("here");
-        let command_buffer = device.command_buffer()?;
-        let command_buffer = &command_buffer;
-        let encoder = command_buffer.encoder();
-        let encoder = encoder.as_ref();
-        encoder.set_compute_pipeline_state(&self.func);
-        let (g, b) = if elem_count % 32 == 0 {
-            (elem_count / 32, 32)
-        } else {
-            (elem_count, 1)
-        };
-        let grid_dims = metal::MTLSize {
-            width: g as u64,
-            height: 1,
-            depth: 1,
-        };
-        let group_dims = candle_metal_kernels::utils::get_block_dims(b as u64, 1, 1);
-        candle_metal_kernels::utils::set_param(encoder, 0, (sto.buffer(), 0usize));
-
-        encoder.use_resource(sto.buffer(), metal::MTLResourceUsage::Write);
-        encoder.dispatch_threads(grid_dims, group_dims);
-
-        Ok(())
-    }
-
-    #[cfg(feature = "cuda")]
-    fn cuda_fwd(&self, sto: &mut CudaStorage, layout: &Layout) -> Result<()> {
-        use crate::cuda_backend::WrapErr;
-        use cudarc::driver::LaunchAsync;
-
-        let elem_count = layout.shape().elem_count();
-        // TODO: support more dtypes.
-        let sto = sto.as_cuda_slice::<f32>()?;
-        let sto = match layout.contiguous_offsets() {
-            None => crate::bail!("input has to be contiguous"),
-            Some((o1, o2)) => sto.slice(o1..o2),
-        };
-        let params = (&sto,);
-        let (g, b) = if elem_count % 32 == 0 {
-            (elem_count / 32, 32)
-        } else {
-            (elem_count, 1)
-        };
-        let cfg = cudarc::driver::LaunchConfig {
-            grid_dim: (g as u32, 1, 1),
-            block_dim: (b as u32, 1, 1),
-            shared_mem_bytes: 0,
-        };
-        unsafe { self.func.clone().launch(cfg, params) }.w()?;
-        Ok(())
-    }
-}
diff --git a/candle-core/src/error.rs b/candle-core/src/error.rs
index 506f85afc..ff75ce65b 100644
--- a/candle-core/src/error.rs
+++ b/candle-core/src/error.rs
@@ -186,9 +186,6 @@ pub enum Error {
     #[error("Metal error {0}")]
     Metal(#[from] MetalError),
 
-    #[error(transparent)]
-    Ug(#[from] ug::Error),
-
     #[error(transparent)]
     TryFromIntError(#[from] core::num::TryFromIntError),