diff --git a/CHANGELOG.md b/CHANGELOG.md
index e8fb5f4..0f7d9a0 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -17,6 +17,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - Improve error message from syn in generator. !15
 - Removed top level module (register_interface), and now it can have arbitrary name.
+- Use full path `RegisterSpec`s to avoid unused `use`
 
 ## [0.3.1] - 2025-04-11
 
diff --git a/src/generator.rs b/src/generator.rs
index 8fa5ff7..94ea55f 100644
--- a/src/generator.rs
+++ b/src/generator.rs
@@ -455,7 +455,6 @@ impl CodeGen for Register {
             use std::marker::PhantomData;
 
             use crate::axic2c1::spec::AxiC2c1Spec;
-            use crate::register_spec::{DataConversionError, Modifiable, Readable, RegisterSpec, Writable};
 
             const OFFSET: usize = #addr;
 
diff --git a/src/generator/codegen_register.rs b/src/generator/codegen_register.rs
index b54e4a9..07533f3 100644
--- a/src/generator/codegen_register.rs
+++ b/src/generator/codegen_register.rs
@@ -76,7 +76,7 @@ fn reg_type_def_masked(
         #[derive(Debug, Clone, Copy, Default)]
         pub struct #upper_camel_name(pub #type_ux);
         impl TryFrom<#type_ux> for #upper_camel_name {
-            type Error = DataConversionError<#type_ux, Self>;
+            type Error = register_spec::DataConversionError<#type_ux, Self>;
 
             fn try_from(value: #type_ux) -> Result<Self, Self::Error> {
                 Ok(Self(value & #mask))
@@ -137,7 +137,7 @@ fn reg_type_def_with_field(
             #(#code_setters)*
         }
         impl TryFrom<#type_ux> for #upper_camel_name {
-            type Error = DataConversionError<#type_ux, Self>;
+            type Error = register_spec::DataConversionError<#type_ux, Self>;
 
             fn try_from(value: #type_ux) -> Result<Self, Self::Error> {
                 Ok(Self { inner: value })
diff --git a/src/generator/codegen_registerspec_impl.rs b/src/generator/codegen_registerspec_impl.rs
index 32604a0..5eca06c 100644
--- a/src/generator/codegen_registerspec_impl.rs
+++ b/src/generator/codegen_registerspec_impl.rs
@@ -11,19 +11,19 @@ pub(super) fn gen_registerspec_impl(
 ) -> TokenStream {
     let impl_rw = match modf {
         RwSpecifier::R => quote! {
-            impl<T: AxiC2c1Spec> Readable for #reg_name<'_, T> {}
+            impl<T: AxiC2c1Spec> register_spec::Readable for #reg_name<'_, T> {}
         },
         RwSpecifier::W => quote! {
-            impl<T: AxiC2c1Spec> Writable for #reg_name<'_, T> {}
+            impl<T: AxiC2c1Spec> register_spec::Writable for #reg_name<'_, T> {}
         },
         RwSpecifier::RW => quote! {
-            impl<T: AxiC2c1Spec> Readable for #reg_name<'_, T> {}
-            impl<T: AxiC2c1Spec> Writable for #reg_name<'_, T> {}
-            impl<T: AxiC2c1Spec> Modifiable for #reg_name<'_, T> {}
+            impl<T: AxiC2c1Spec> register_spec::Readable for #reg_name<'_, T> {}
+            impl<T: AxiC2c1Spec> register_spec::Writable for #reg_name<'_, T> {}
+            impl<T: AxiC2c1Spec> register_spec::Modifiable for #reg_name<'_, T> {}
         },
     };
     quote! {
-        impl<T: AxiC2c1Spec> RegisterSpec for #reg_name<'_, T> {
+        impl<T: AxiC2c1Spec> register_spec::RegisterSpec for #reg_name<'_, T> {
             type Ux = #type_ux;
             type T = #type_t;