diff --git a/rust-version b/rust-version
index 8afb8e9823..3930fa0e94 100644
--- a/rust-version
+++ b/rust-version
@@ -1 +1 @@
-639377ed737b25830ec44dc6acf93467c980316a
+3eb5c4581a386b13c414e8c8bd73846ef37236d1
diff --git a/src/eval.rs b/src/eval.rs
index d61e17cbf9..ebb71b57ae 100644
--- a/src/eval.rs
+++ b/src/eval.rs
@@ -363,7 +363,7 @@ pub fn create_ecx<'mir, 'tcx: 'mir>(
                 tcx,
                 ty::ParamEnv::reveal_all(),
                 start_id,
-                tcx.mk_substs(::std::iter::once(ty::subst::GenericArg::from(main_ret_ty))),
+                tcx.intern_substs(&[ty::subst::GenericArg::from(main_ret_ty)]),
             )
             .unwrap()
             .unwrap();
diff --git a/src/machine.rs b/src/machine.rs
index 269b441c50..f9a6ef34c2 100644
--- a/src/machine.rs
+++ b/src/machine.rs
@@ -907,8 +907,8 @@ impl<'mir, 'tcx> Machine<'mir, 'tcx> for MiriMachine<'mir, 'tcx> {
                 panic!("extern_statics cannot contain wildcards")
             };
             let (shim_size, shim_align, _kind) = ecx.get_alloc_info(alloc_id);
-            let extern_decl_layout =
-                ecx.tcx.layout_of(ty::ParamEnv::empty().and(ecx.tcx.type_of(def_id))).unwrap();
+            let def_ty = ecx.tcx.type_of(def_id).subst_identity();
+            let extern_decl_layout = ecx.tcx.layout_of(ty::ParamEnv::empty().and(def_ty)).unwrap();
             if extern_decl_layout.size != shim_size || extern_decl_layout.align.abi != shim_align {
                 throw_unsup_format!(
                     "`extern` static `{name}` from crate `{krate}` has been declared \