diff --git a/crates/compiler/can/src/def.rs b/crates/compiler/can/src/def.rs
index bd87232166..728124d1c9 100644
--- a/crates/compiler/can/src/def.rs
+++ b/crates/compiler/can/src/def.rs
@@ -823,7 +823,7 @@ fn canonicalize_opaque<'a>(
                 let mut impls = Vec::with_capacity(num_members);
                 for &member in members.iter() {
                     let (derived_impl, impl_pat, impl_body) =
-                        derive::synthesize_member_impl(env, scope, name.value, name_str, member);
+                        derive::synthesize_member_impl(env, scope, name_str, member);
 
                     let derived_def = Loc::at(
                         derive::DERIVED_REGION,
diff --git a/crates/compiler/can/src/derive.rs b/crates/compiler/can/src/derive.rs
index 88e371d974..b2bda1b2e0 100644
--- a/crates/compiler/can/src/derive.rs
+++ b/crates/compiler/can/src/derive.rs
@@ -151,7 +151,6 @@ pub(crate) const DERIVED_REGION: Region = Region::zero();
 pub(crate) fn synthesize_member_impl<'a>(
     env: &mut Env<'a>,
     scope: &mut Scope,
-    opaque: Symbol,
     opaque_name: &'a str,
     ability_member: Symbol,
 ) -> (Symbol, Loc<Pattern>, &'a Loc<ast::Expr<'a>>) {