diff --git a/compiler/rustc_next_trait_solver/src/delegate.rs b/compiler/rustc_next_trait_solver/src/delegate.rs
index 2d2d50e62f9..196c83c8c51 100644
--- a/compiler/rustc_next_trait_solver/src/delegate.rs
+++ b/compiler/rustc_next_trait_solver/src/delegate.rs
@@ -11,8 +11,6 @@ pub trait SolverDelegate: Deref<Target = <Self as SolverDelegate>::Infcx> + Size
         (**self).cx()
     }
 
-    type Span: Copy;
-
     fn build_with_canonical<V>(
         cx: Self::Interner,
         canonical: &ty::CanonicalQueryInput<Self::Interner, V>,
@@ -23,7 +21,7 @@ pub trait SolverDelegate: Deref<Target = <Self as SolverDelegate>::Infcx> + Size
     fn fresh_var_for_kind_with_span(
         &self,
         arg: <Self::Interner as Interner>::GenericArg,
-        span: Self::Span,
+        span: <Self::Interner as Interner>::Span,
     ) -> <Self::Interner as Interner>::GenericArg;
 
     // FIXME: Uplift the leak check into this crate.
diff --git a/compiler/rustc_next_trait_solver/src/solve/eval_ctxt/canonical.rs b/compiler/rustc_next_trait_solver/src/solve/eval_ctxt/canonical.rs
index e99cd3d2727..629be3f3d45 100644
--- a/compiler/rustc_next_trait_solver/src/solve/eval_ctxt/canonical.rs
+++ b/compiler/rustc_next_trait_solver/src/solve/eval_ctxt/canonical.rs
@@ -431,7 +431,7 @@ where
 // `rustc_trait_selection::solve::inspect::analyse`.
 pub fn instantiate_canonical_state<D, I, T: TypeFoldable<I>>(
     delegate: &D,
-    span: D::Span,
+    span: I::Span,
     param_env: I::ParamEnv,
     orig_values: &mut Vec<I::GenericArg>,
     state: inspect::CanonicalState<I, T>,
diff --git a/compiler/rustc_trait_selection/src/solve/delegate.rs b/compiler/rustc_trait_selection/src/solve/delegate.rs
index abb79493432..36e3d719e85 100644
--- a/compiler/rustc_trait_selection/src/solve/delegate.rs
+++ b/compiler/rustc_trait_selection/src/solve/delegate.rs
@@ -43,8 +43,6 @@ impl<'tcx> rustc_next_trait_solver::delegate::SolverDelegate for SolverDelegate<
         self.0.tcx
     }
 
-    type Span = Span;
-
     fn build_with_canonical<V>(
         interner: TyCtxt<'tcx>,
         canonical: &CanonicalQueryInput<'tcx, V>,