diff --git a/src/generator/codegen_register.rs b/src/generator/codegen_register.rs
index 78029b0..0cff61d 100644
--- a/src/generator/codegen_register.rs
+++ b/src/generator/codegen_register.rs
@@ -297,7 +297,7 @@ fn generate_single_ux_field(
     };
     let code_setter = quote! {
         pub fn #setter_name(&self, val: #field_type) -> Self {
-            let update: #base_type = val & #mask_name;
+            let update: #base_type = (val as #base_type) & #mask_name;
             let mut inner = self.inner;
             inner &= !#mask_name;
             inner |= update;