diff --git a/example/demo_gen/demo/FixedDecimal.mjs b/example/demo_gen/demo/FixedDecimal.mjs
index 8b1a9c1aa..428f1d642 100644
--- a/example/demo_gen/demo/FixedDecimal.mjs
+++ b/example/demo_gen/demo/FixedDecimal.mjs
@@ -1,13 +1,12 @@
 import { FixedDecimal } from "../../js/lib/api/index.mjs"
 export function toString(v) {
-    var terminusArgs = arguments;
     return (function (...args) { return args[0].toString(...args.slice(1)) }).apply(
         null,
         [
             FixedDecimal.new_.apply(
                 null,
                 [
-                    terminusArgs[0]
+                    v
                 ]
             )
         ]
diff --git a/example/demo_gen/demo/FixedDecimalFormatter.mjs b/example/demo_gen/demo/FixedDecimalFormatter.mjs
index f8c156179..312cca8fd 100644
--- a/example/demo_gen/demo/FixedDecimalFormatter.mjs
+++ b/example/demo_gen/demo/FixedDecimalFormatter.mjs
@@ -4,7 +4,6 @@ import { FixedDecimalFormatter } from "../../js/lib/api/index.mjs"
 import { FixedDecimalFormatterOptions } from "../../js/lib/api/index.mjs"
 import { Locale } from "../../js/lib/api/index.mjs"
 export function formatWrite(name, grouping_strategy, some_other_config, v) {
-    var terminusArgs = arguments;
     return (function (...args) { return args[0].formatWrite(...args.slice(1)) }).apply(
         null,
         [
@@ -14,7 +13,7 @@ export function formatWrite(name, grouping_strategy, some_other_config, v) {
                     Locale.new_.apply(
                         null,
                         [
-                            terminusArgs[0]
+                            name
                         ]
                     ),
                     DataProvider.newStatic.apply(
@@ -27,8 +26,8 @@ export function formatWrite(name, grouping_strategy, some_other_config, v) {
                     }).apply(
                         null,
                         [
-                            terminusArgs[1],
-                            terminusArgs[2]
+                            grouping_strategy,
+                            some_other_config
                         ]
                     )
                 ]
@@ -36,7 +35,7 @@ export function formatWrite(name, grouping_strategy, some_other_config, v) {
             FixedDecimal.new_.apply(
                 null,
                 [
-                    terminusArgs[3]
+                    v
                 ]
             )
         ]
diff --git a/feature_tests/demo_gen/demo/Float64Vec.mjs b/feature_tests/demo_gen/demo/Float64Vec.mjs
index 26b6df6a9..f321848ce 100644
--- a/feature_tests/demo_gen/demo/Float64Vec.mjs
+++ b/feature_tests/demo_gen/demo/Float64Vec.mjs
@@ -1,13 +1,12 @@
 import { Float64Vec } from "../../js/api/index.mjs"
 export function toString(v) {
-    var terminusArgs = arguments;
     return (function (...args) { return args[0].toString(...args.slice(1)) }).apply(
         null,
         [
             Float64Vec.newFromOwned.apply(
                 null,
                 [
-                    terminusArgs[0]
+                    v
                 ]
             )
         ]
diff --git a/feature_tests/demo_gen/demo/MyString.mjs b/feature_tests/demo_gen/demo/MyString.mjs
index 8888a5e11..efba98356 100644
--- a/feature_tests/demo_gen/demo/MyString.mjs
+++ b/feature_tests/demo_gen/demo/MyString.mjs
@@ -1,24 +1,22 @@
 import { MyString } from "../../js/api/index.mjs"
 export function getStr(v) {
-    var terminusArgs = arguments;
     return (function (...args) { return args[0].getStr }).apply(
         null,
         [
             MyString.new_.apply(
                 null,
                 [
-                    terminusArgs[0]
+                    v
                 ]
             )
         ]
     );
 }
 export function stringTransform(foo) {
-    var terminusArgs = arguments;
     return MyString.stringTransform.apply(
         null,
         [
-            terminusArgs[0]
+            foo
         ]
     );
 }
diff --git a/feature_tests/demo_gen/demo/Opaque.mjs b/feature_tests/demo_gen/demo/Opaque.mjs
index 885269b7b..626b27275 100644
--- a/feature_tests/demo_gen/demo/Opaque.mjs
+++ b/feature_tests/demo_gen/demo/Opaque.mjs
@@ -1,6 +1,5 @@
 import { Opaque } from "../../js/api/index.mjs"
 export function getDebugStr() {
-    var terminusArgs = arguments;
     return (function (...args) { return args[0].getDebugStr(...args.slice(1)) }).apply(
         null,
         [
diff --git a/feature_tests/demo_gen/demo/OptionString.mjs b/feature_tests/demo_gen/demo/OptionString.mjs
index 758b34558..d4401ca8b 100644
--- a/feature_tests/demo_gen/demo/OptionString.mjs
+++ b/feature_tests/demo_gen/demo/OptionString.mjs
@@ -1,13 +1,12 @@
 import { OptionString } from "../../js/api/index.mjs"
 export function write(diplomatStr) {
-    var terminusArgs = arguments;
     return (function (...args) { return args[0].write(...args.slice(1)) }).apply(
         null,
         [
             OptionString.new_.apply(
                 null,
                 [
-                    terminusArgs[0]
+                    diplomatStr
                 ]
             )
         ]
diff --git a/feature_tests/demo_gen/demo/Utf16Wrap.mjs b/feature_tests/demo_gen/demo/Utf16Wrap.mjs
index 98367298b..0ba39fba7 100644
--- a/feature_tests/demo_gen/demo/Utf16Wrap.mjs
+++ b/feature_tests/demo_gen/demo/Utf16Wrap.mjs
@@ -1,13 +1,12 @@
 import { Utf16Wrap } from "../../js/api/index.mjs"
 export function getDebugStr(input) {
-    var terminusArgs = arguments;
     return (function (...args) { return args[0].getDebugStr(...args.slice(1)) }).apply(
         null,
         [
             Utf16Wrap.fromUtf16.apply(
                 null,
                 [
-                    terminusArgs[0]
+                    input
                 ]
             )
         ]