diff --git a/compiler/rustc_trait_selection/src/traits/wf.rs b/compiler/rustc_trait_selection/src/traits/wf.rs
index 5553490542b75..5f9b967a5d095 100644
--- a/compiler/rustc_trait_selection/src/traits/wf.rs
+++ b/compiler/rustc_trait_selection/src/traits/wf.rs
@@ -493,7 +493,7 @@ impl<'a, 'tcx> WfPredicates<'a, 'tcx> {
             self.out.extend(obligations);
         }
 
-        self.compute_projection_args(data.args);
+        data.args.visit_with(self);
     }
 
     fn compute_projection_args(&mut self, args: GenericArgsRef<'tcx>) {
@@ -698,8 +698,8 @@ impl<'a, 'tcx> TypeVisitor<TyCtxt<'tcx>> for WfPredicates<'a, 'tcx> {
             }
 
             ty::Alias(ty::Projection | ty::Opaque | ty::Weak, data) => {
-                self.compute_alias(data);
-                return; // Subtree handled by compute_projection.
+                let obligations = self.nominal_obligations(data.def_id, data.args);
+                self.out.extend(obligations);
             }
             ty::Alias(ty::Inherent, data) => {
                 self.compute_inherent_projection(data);