diff --git a/compiler/lib/js_traverse.ml b/compiler/lib/js_traverse.ml
index 6df0f8b314..d7714ab2fd 100644
--- a/compiler/lib/js_traverse.ml
+++ b/compiler/lib/js_traverse.ml
@@ -1220,7 +1220,6 @@ class simpl =
     inherit map as super
 
     method expression e =
-      let e = super#expression e in
       let is_zero x =
         match Num.to_string x with
         | "0" | "0." -> true
@@ -1228,6 +1227,7 @@ class simpl =
       in
       match e with
       | EBin (Plus, e1, e2) -> (
+          let e = super#expression e in
           match e2, e1 with
           | ENum n, _ when Num.is_neg n -> EBin (Minus, e1, ENum (Num.neg n))
           | _, ENum n when Num.is_neg n -> EBin (Minus, e2, ENum (Num.neg n))
@@ -1235,12 +1235,13 @@ class simpl =
           | (ENum _ as x), ENum zero when is_zero zero -> x
           | _ -> e)
       | EBin (Minus, e1, e2) -> (
+          let e = super#expression e in
           match e2, e1 with
           | ENum n, _ when Num.is_neg n -> EBin (Plus, e1, ENum (Num.neg n))
           | (ENum _ as x), ENum zero when is_zero zero -> x
           | _ -> e)
       | EFun (i, k, p, b, l) -> EFun (i, k, p, m#statements_top b, l)
-      | _ -> e
+      | _ -> super#expression e
 
     method statement s =
       let s = super#statement s in
@@ -1248,9 +1249,7 @@ class simpl =
       | Block [ x ] -> fst x
       | _ -> s
 
-    method program p =
-      let p = super#statements p in
-      m#statements_top p
+    method program p = m#statements_top p
 
     method private statements_top l =
       (* In strict mode, functions inside blocks are scoped to that
@@ -1266,35 +1265,41 @@ class simpl =
              | s -> s, loc))
 
     method statements s =
-      let s = super#statements s in
       List.fold_right s ~init:[] ~f:(fun (st, loc) rem ->
           match st with
           | Function_declaration (i, k, p, b, l) ->
               (Function_declaration (i, k, p, m#statements_top b, l), loc) :: rem
-          | If_statement (ENum n, iftrue, _) when Num.is_one n -> iftrue :: rem
-          | If_statement (ENum n, _, iffalse) when Num.is_zero n -> opt_cons iffalse rem
-          | If_statement
-              (cond, (Return_statement (Some e1), _), Some (Return_statement (Some e2), _))
-            -> (Return_statement (Some (ECond (cond, e1, e2))), loc) :: rem
-          | If_statement
-              ( cond
-              , (Expression_statement (EBin (Eq, v1, e1)), _)
-              , Some (Expression_statement (EBin (Eq, v2, e2)), _) )
-            when Poly.(v1 = v2) ->
-              (Expression_statement (EBin (Eq, v1, ECond (cond, e1, e2))), loc) :: rem
-          | Variable_statement ((Var as k), l1) ->
-              let x =
-                List.map l1 ~f:(function
-                    | DPattern (p, e) -> Variable_statement (k, [ DPattern (p, e) ]), loc
-                    | DIdent (ident, None) ->
-                        Variable_statement (k, [ DIdent (ident, None) ]), loc
-                    | DIdent (ident, Some (exp, pc)) -> (
-                        match assign_op (EVar ident, exp) with
-                        | Some e -> Expression_statement e, loc
-                        | None ->
-                            ( Variable_statement (k, [ DIdent (ident, Some (exp, pc)) ])
-                            , loc )))
-              in
-              x @ rem
-          | _ -> (st, loc) :: rem)
+          | s -> (
+              match super#statement s with
+              | If_statement (ENum n, iftrue, _) when Num.is_one n -> iftrue :: rem
+              | If_statement (ENum n, _, iffalse) when Num.is_zero n ->
+                  opt_cons iffalse rem
+              | If_statement
+                  ( cond
+                  , (Return_statement (Some e1), _)
+                  , Some (Return_statement (Some e2), _) ) ->
+                  (Return_statement (Some (ECond (cond, e1, e2))), loc) :: rem
+              | If_statement
+                  ( cond
+                  , (Expression_statement (EBin (Eq, v1, e1)), _)
+                  , Some (Expression_statement (EBin (Eq, v2, e2)), _) )
+                when Poly.(v1 = v2) ->
+                  (Expression_statement (EBin (Eq, v1, ECond (cond, e1, e2))), loc) :: rem
+              | Variable_statement ((Var as k), l1) ->
+                  let x =
+                    List.map l1 ~f:(function
+                        | DPattern (p, e) ->
+                            Variable_statement (k, [ DPattern (p, e) ]), loc
+                        | DIdent (ident, None) ->
+                            Variable_statement (k, [ DIdent (ident, None) ]), loc
+                        | DIdent (ident, Some (exp, pc)) -> (
+                            match assign_op (EVar ident, exp) with
+                            | Some e -> Expression_statement e, loc
+                            | None ->
+                                ( Variable_statement
+                                    (k, [ DIdent (ident, Some (exp, pc)) ])
+                                , loc )))
+                  in
+                  x @ rem
+              | _ -> (st, loc) :: rem))
   end