diff --git a/compiler/rustc_hir_analysis/src/astconv/mod.rs b/compiler/rustc_hir_analysis/src/astconv/mod.rs
index 66891a910268d..4dde2aa0da535 100644
--- a/compiler/rustc_hir_analysis/src/astconv/mod.rs
+++ b/compiler/rustc_hir_analysis/src/astconv/mod.rs
@@ -1641,10 +1641,8 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
                                 let impl_ty = ocx.normalize(&cause, param_env, impl_ty);
 
                                 // Check that the self types can be related.
-                                // FIXME(inherent_associated_types): Should we use `eq` here? Method probing uses
-                                // `sup` for this situtation, too. What for? To constrain inference variables?
                                 if ocx
-                                    .sup(&ObligationCause::dummy(), param_env, impl_ty, self_ty)
+                                    .eq(&ObligationCause::dummy(), param_env, impl_ty, self_ty)
                                     .is_err()
                                 {
                                     return false;