diff --git a/compiler/rustc_middle/src/ty/walk.rs b/compiler/rustc_middle/src/ty/walk.rs
index 182945b9c3db..04a635a68034 100644
--- a/compiler/rustc_middle/src/ty/walk.rs
+++ b/compiler/rustc_middle/src/ty/walk.rs
@@ -194,7 +194,7 @@ fn push_inner<'tcx>(stack: &mut TypeWalkerStack<'tcx>, parent: GenericArg<'tcx>)
             | ty::FnDef(_, substs) => {
                 stack.extend(substs.iter().rev());
             }
-            ty::Tuple(ts) => stack.extend(ts.as_substs().iter().rev()),
+            ty::Tuple(ts) => stack.extend(ts.iter().rev().map(GenericArg::from)),
             ty::GeneratorWitness(ts) => {
                 stack.extend(ts.skip_binder().iter().rev().map(|ty| ty.into()));
             }