diff --git a/src/boot/me/semant.ml b/src/boot/me/semant.ml
index 031f1b40525..cb11991fd93 100644
--- a/src/boot/me/semant.ml
+++ b/src/boot/me/semant.ml
@@ -1066,12 +1066,19 @@ let check_concrete params thing =
   else bug () "unhandled parametric binding"
 ;;
 
+let rec simplified_ty (t:Ast.ty) : Ast.ty =
+  match t with
+      Ast.TY_exterior t
+    | Ast.TY_mutable t
+    | Ast.TY_constrained (t, _) -> simplified_ty t
+    | _ -> t
+;;
 
 let project_type
     (base_ty:Ast.ty)
     (comp:Ast.lval_component)
     : Ast.ty =
-  match (base_ty, comp) with
+  match (simplified_ty base_ty, comp) with
       (Ast.TY_rec elts, Ast.COMP_named (Ast.COMP_ident id)) ->
         begin
           match atab_search elts id with
diff --git a/src/boot/me/trans.ml b/src/boot/me/trans.ml
index e409602a69e..e33e3ed4f11 100644
--- a/src/boot/me/trans.ml
+++ b/src/boot/me/trans.ml
@@ -1887,12 +1887,12 @@ let trans_visitor
     in
       match expr with
           Ast.EXPR_binary (binop, a, b) ->
-            assert (is_prim_type (atom_type cx a));
-            assert (is_prim_type (atom_type cx b));
+            assert (is_prim_type (simplified_ty (atom_type cx a)));
+            assert (is_prim_type (simplified_ty (atom_type cx b)));
             trans_binary binop (trans_atom a) (trans_atom b)
 
         | Ast.EXPR_unary (unop, a) ->
-            assert (is_prim_type (atom_type cx a));
+            assert (is_prim_type (simplified_ty (atom_type cx a)));
             let src = trans_atom a in
             let bits = Il.operand_bits word_bits src in
             let dst = Il.Reg (Il.next_vreg (emitter()), Il.ValTy bits) in
@@ -2218,13 +2218,6 @@ let trans_visitor
   and exterior_rc_cell (cell:Il.cell) : Il.cell =
     exterior_ctrl_cell cell Abi.exterior_rc_slot_field_refcnt
 
-  and simplified_ty t =
-    match t with
-        Ast.TY_exterior t
-      | Ast.TY_mutable t
-      | Ast.TY_constrained (t, _) -> simplified_ty t
-      | _ -> t
-
   and exterior_allocation_size
       (ty:Ast.ty)
       : Il.operand =
@@ -4074,7 +4067,7 @@ let trans_visitor
 
 
   and trans_log id a =
-    match atom_type cx a with
+    match simplified_ty (atom_type cx a) with
         (* NB: If you extend this, be sure to update the
          * typechecking code in type.ml as well. *)
         Ast.TY_str -> trans_log_str a