diff --git a/scripts/setup_rust_fork.sh b/scripts/setup_rust_fork.sh
index e6bbac647e5..f09b9ef12de 100644
--- a/scripts/setup_rust_fork.sh
+++ b/scripts/setup_rust_fork.sh
@@ -31,7 +31,7 @@ index d95b5b7f17f..00b6f0e3635 100644
 EOF
 
 cat > config.toml <<EOF
-changelog-seen = 2
+change-id = 115898
 
 [llvm]
 ninja = false
diff --git a/src/abi/mod.rs b/src/abi/mod.rs
index bd56c3bd34c..c75ad852f82 100644
--- a/src/abi/mod.rs
+++ b/src/abi/mod.rs
@@ -28,7 +28,7 @@ fn clif_sig_from_fn_abi<'tcx>(
     let inputs = fn_abi.args.iter().flat_map(|arg_abi| arg_abi.get_abi_param(tcx).into_iter());
 
     let (return_ptr, returns) = fn_abi.ret.get_abi_return(tcx);
-    // Sometimes the first param is an pointer to the place where the return value needs to be stored.
+    // Sometimes the first param is a pointer to the place where the return value needs to be stored.
     let params: Vec<_> = return_ptr.into_iter().chain(inputs).collect();
 
     Signature { params, returns, call_conv }
diff --git a/src/base.rs b/src/base.rs
index 43afba6322f..ac7389792c8 100644
--- a/src/base.rs
+++ b/src/base.rs
@@ -249,17 +249,6 @@ pub(crate) fn verify_func(
 }
 
 fn codegen_fn_body(fx: &mut FunctionCx<'_, '_, '_>, start_block: Block) {
-    if let Err(err) =
-        fx.mir.post_mono_checks(fx.tcx, ty::ParamEnv::reveal_all(), |c| Ok(fx.monomorphize(c)))
-    {
-        err.emit_err(fx.tcx);
-        fx.bcx.append_block_params_for_function_params(fx.block_map[START_BLOCK]);
-        fx.bcx.switch_to_block(fx.block_map[START_BLOCK]);
-        // compilation should have been aborted
-        fx.bcx.ins().trap(TrapCode::UnreachableCodeReached);
-        return;
-    }
-
     let arg_uninhabited = fx
         .mir
         .args_iter()
@@ -875,6 +864,7 @@ pub(crate) fn codegen_place<'tcx>(
                 cplace = cplace.place_deref(fx);
             }
             PlaceElem::OpaqueCast(ty) => bug!("encountered OpaqueCast({ty}) in codegen"),
+            PlaceElem::Subtype(ty) => cplace = cplace.place_transmute_type(fx, fx.monomorphize(ty)),
             PlaceElem::Field(field, _ty) => {
                 cplace = cplace.place_field(fx, field);
             }
diff --git a/src/value_and_place.rs b/src/value_and_place.rs
index bc7a6f1d591..3a6a6c9e3f5 100644
--- a/src/value_and_place.rs
+++ b/src/value_and_place.rs
@@ -674,6 +674,16 @@ impl<'tcx> CPlace<'tcx> {
         }
     }
 
+    /// Used for `ProjectionElem::Subtype`, `ty` has to be monomorphized before
+    /// passed on.
+    pub(crate) fn place_transmute_type(
+        self,
+        fx: &mut FunctionCx<'_, '_, 'tcx>,
+        ty: Ty<'tcx>,
+    ) -> CPlace<'tcx> {
+        CPlace { inner: self.inner, layout: fx.layout_of(ty) }
+    }
+
     pub(crate) fn place_field(
         self,
         fx: &mut FunctionCx<'_, '_, 'tcx>,