diff --git a/baselines/audioworklet.generated.d.ts b/baselines/audioworklet.generated.d.ts
index be0c723c6..d871cf03c 100644
--- a/baselines/audioworklet.generated.d.ts
+++ b/baselines/audioworklet.generated.d.ts
@@ -1227,7 +1227,7 @@ interface TransformStreamDefaultController<O = any> {
      *
      * [MDN Reference](https://developer.mozilla.org/docs/Web/API/TransformStreamDefaultController/enqueue)
      */
-    enqueue(chunk?: O): void;
+    enqueue(chunk: O): void;
     /**
      * The **`error()`** method of the TransformStreamDefaultController interface errors both sides of the stream. Any further interactions with it will fail with the given error message, and any chunks in the queue will be discarded.
      *
@@ -1537,7 +1537,7 @@ interface WritableStreamDefaultWriter<W = any> {
      *
      * [MDN Reference](https://developer.mozilla.org/docs/Web/API/WritableStreamDefaultWriter/write)
      */
-    write(chunk?: W): Promise<void>;
+    write(chunk: W): Promise<void>;
 }
 
 declare var WritableStreamDefaultWriter: {
diff --git a/baselines/dom.generated.d.ts b/baselines/dom.generated.d.ts
index d595d78b9..67df663b2 100644
--- a/baselines/dom.generated.d.ts
+++ b/baselines/dom.generated.d.ts
@@ -37250,7 +37250,7 @@ interface TransformStreamDefaultController<O = any> {
      *
      * [MDN Reference](https://developer.mozilla.org/docs/Web/API/TransformStreamDefaultController/enqueue)
      */
-    enqueue(chunk?: O): void;
+    enqueue(chunk: O): void;
     /**
      * The **`error()`** method of the TransformStreamDefaultController interface errors both sides of the stream. Any further interactions with it will fail with the given error message, and any chunks in the queue will be discarded.
      *
@@ -42094,7 +42094,7 @@ interface WritableStreamDefaultWriter<W = any> {
      *
      * [MDN Reference](https://developer.mozilla.org/docs/Web/API/WritableStreamDefaultWriter/write)
      */
-    write(chunk?: W): Promise<void>;
+    write(chunk: W): Promise<void>;
 }
 
 declare var WritableStreamDefaultWriter: {
diff --git a/baselines/serviceworker.generated.d.ts b/baselines/serviceworker.generated.d.ts
index 90b838669..d1f341b8f 100644
--- a/baselines/serviceworker.generated.d.ts
+++ b/baselines/serviceworker.generated.d.ts
@@ -9313,7 +9313,7 @@ interface TransformStreamDefaultController<O = any> {
      *
      * [MDN Reference](https://developer.mozilla.org/docs/Web/API/TransformStreamDefaultController/enqueue)
      */
-    enqueue(chunk?: O): void;
+    enqueue(chunk: O): void;
     /**
      * The **`error()`** method of the TransformStreamDefaultController interface errors both sides of the stream. Any further interactions with it will fail with the given error message, and any chunks in the queue will be discarded.
      *
@@ -12766,7 +12766,7 @@ interface WritableStreamDefaultWriter<W = any> {
      *
      * [MDN Reference](https://developer.mozilla.org/docs/Web/API/WritableStreamDefaultWriter/write)
      */
-    write(chunk?: W): Promise<void>;
+    write(chunk: W): Promise<void>;
 }
 
 declare var WritableStreamDefaultWriter: {
diff --git a/baselines/sharedworker.generated.d.ts b/baselines/sharedworker.generated.d.ts
index dd83d4fdc..27b210acd 100644
--- a/baselines/sharedworker.generated.d.ts
+++ b/baselines/sharedworker.generated.d.ts
@@ -8844,7 +8844,7 @@ interface TransformStreamDefaultController<O = any> {
      *
      * [MDN Reference](https://developer.mozilla.org/docs/Web/API/TransformStreamDefaultController/enqueue)
      */
-    enqueue(chunk?: O): void;
+    enqueue(chunk: O): void;
     /**
      * The **`error()`** method of the TransformStreamDefaultController interface errors both sides of the stream. Any further interactions with it will fail with the given error message, and any chunks in the queue will be discarded.
      *
@@ -12305,7 +12305,7 @@ interface WritableStreamDefaultWriter<W = any> {
      *
      * [MDN Reference](https://developer.mozilla.org/docs/Web/API/WritableStreamDefaultWriter/write)
      */
-    write(chunk?: W): Promise<void>;
+    write(chunk: W): Promise<void>;
 }
 
 declare var WritableStreamDefaultWriter: {
diff --git a/baselines/ts5.5/audioworklet.generated.d.ts b/baselines/ts5.5/audioworklet.generated.d.ts
index dbe38b1ad..d8072fdfe 100644
--- a/baselines/ts5.5/audioworklet.generated.d.ts
+++ b/baselines/ts5.5/audioworklet.generated.d.ts
@@ -1224,7 +1224,7 @@ interface TransformStreamDefaultController<O = any> {
      *
      * [MDN Reference](https://developer.mozilla.org/docs/Web/API/TransformStreamDefaultController/enqueue)
      */
-    enqueue(chunk?: O): void;
+    enqueue(chunk: O): void;
     /**
      * The **`error()`** method of the TransformStreamDefaultController interface errors both sides of the stream. Any further interactions with it will fail with the given error message, and any chunks in the queue will be discarded.
      *
@@ -1534,7 +1534,7 @@ interface WritableStreamDefaultWriter<W = any> {
      *
      * [MDN Reference](https://developer.mozilla.org/docs/Web/API/WritableStreamDefaultWriter/write)
      */
-    write(chunk?: W): Promise<void>;
+    write(chunk: W): Promise<void>;
 }
 
 declare var WritableStreamDefaultWriter: {
diff --git a/baselines/ts5.5/dom.generated.d.ts b/baselines/ts5.5/dom.generated.d.ts
index af2361703..fcab6f0c9 100644
--- a/baselines/ts5.5/dom.generated.d.ts
+++ b/baselines/ts5.5/dom.generated.d.ts
@@ -37224,7 +37224,7 @@ interface TransformStreamDefaultController<O = any> {
      *
      * [MDN Reference](https://developer.mozilla.org/docs/Web/API/TransformStreamDefaultController/enqueue)
      */
-    enqueue(chunk?: O): void;
+    enqueue(chunk: O): void;
     /**
      * The **`error()`** method of the TransformStreamDefaultController interface errors both sides of the stream. Any further interactions with it will fail with the given error message, and any chunks in the queue will be discarded.
      *
@@ -42068,7 +42068,7 @@ interface WritableStreamDefaultWriter<W = any> {
      *
      * [MDN Reference](https://developer.mozilla.org/docs/Web/API/WritableStreamDefaultWriter/write)
      */
-    write(chunk?: W): Promise<void>;
+    write(chunk: W): Promise<void>;
 }
 
 declare var WritableStreamDefaultWriter: {
diff --git a/baselines/ts5.5/serviceworker.generated.d.ts b/baselines/ts5.5/serviceworker.generated.d.ts
index 9d420a826..ae05b3ddf 100644
--- a/baselines/ts5.5/serviceworker.generated.d.ts
+++ b/baselines/ts5.5/serviceworker.generated.d.ts
@@ -9310,7 +9310,7 @@ interface TransformStreamDefaultController<O = any> {
      *
      * [MDN Reference](https://developer.mozilla.org/docs/Web/API/TransformStreamDefaultController/enqueue)
      */
-    enqueue(chunk?: O): void;
+    enqueue(chunk: O): void;
     /**
      * The **`error()`** method of the TransformStreamDefaultController interface errors both sides of the stream. Any further interactions with it will fail with the given error message, and any chunks in the queue will be discarded.
      *
@@ -12763,7 +12763,7 @@ interface WritableStreamDefaultWriter<W = any> {
      *
      * [MDN Reference](https://developer.mozilla.org/docs/Web/API/WritableStreamDefaultWriter/write)
      */
-    write(chunk?: W): Promise<void>;
+    write(chunk: W): Promise<void>;
 }
 
 declare var WritableStreamDefaultWriter: {
diff --git a/baselines/ts5.5/sharedworker.generated.d.ts b/baselines/ts5.5/sharedworker.generated.d.ts
index 72b0b45ae..227dc54d1 100644
--- a/baselines/ts5.5/sharedworker.generated.d.ts
+++ b/baselines/ts5.5/sharedworker.generated.d.ts
@@ -8841,7 +8841,7 @@ interface TransformStreamDefaultController<O = any> {
      *
      * [MDN Reference](https://developer.mozilla.org/docs/Web/API/TransformStreamDefaultController/enqueue)
      */
-    enqueue(chunk?: O): void;
+    enqueue(chunk: O): void;
     /**
      * The **`error()`** method of the TransformStreamDefaultController interface errors both sides of the stream. Any further interactions with it will fail with the given error message, and any chunks in the queue will be discarded.
      *
@@ -12302,7 +12302,7 @@ interface WritableStreamDefaultWriter<W = any> {
      *
      * [MDN Reference](https://developer.mozilla.org/docs/Web/API/WritableStreamDefaultWriter/write)
      */
-    write(chunk?: W): Promise<void>;
+    write(chunk: W): Promise<void>;
 }
 
 declare var WritableStreamDefaultWriter: {
diff --git a/baselines/ts5.5/webworker.generated.d.ts b/baselines/ts5.5/webworker.generated.d.ts
index 092fb7a1b..3298efb4c 100644
--- a/baselines/ts5.5/webworker.generated.d.ts
+++ b/baselines/ts5.5/webworker.generated.d.ts
@@ -10468,7 +10468,7 @@ interface TransformStreamDefaultController<O = any> {
      *
      * [MDN Reference](https://developer.mozilla.org/docs/Web/API/TransformStreamDefaultController/enqueue)
      */
-    enqueue(chunk?: O): void;
+    enqueue(chunk: O): void;
     /**
      * The **`error()`** method of the TransformStreamDefaultController interface errors both sides of the stream. Any further interactions with it will fail with the given error message, and any chunks in the queue will be discarded.
      *
@@ -14251,7 +14251,7 @@ interface WritableStreamDefaultWriter<W = any> {
      *
      * [MDN Reference](https://developer.mozilla.org/docs/Web/API/WritableStreamDefaultWriter/write)
      */
-    write(chunk?: W): Promise<void>;
+    write(chunk: W): Promise<void>;
 }
 
 declare var WritableStreamDefaultWriter: {
diff --git a/baselines/ts5.6/audioworklet.generated.d.ts b/baselines/ts5.6/audioworklet.generated.d.ts
index dbe38b1ad..d8072fdfe 100644
--- a/baselines/ts5.6/audioworklet.generated.d.ts
+++ b/baselines/ts5.6/audioworklet.generated.d.ts
@@ -1224,7 +1224,7 @@ interface TransformStreamDefaultController<O = any> {
      *
      * [MDN Reference](https://developer.mozilla.org/docs/Web/API/TransformStreamDefaultController/enqueue)
      */
-    enqueue(chunk?: O): void;
+    enqueue(chunk: O): void;
     /**
      * The **`error()`** method of the TransformStreamDefaultController interface errors both sides of the stream. Any further interactions with it will fail with the given error message, and any chunks in the queue will be discarded.
      *
@@ -1534,7 +1534,7 @@ interface WritableStreamDefaultWriter<W = any> {
      *
      * [MDN Reference](https://developer.mozilla.org/docs/Web/API/WritableStreamDefaultWriter/write)
      */
-    write(chunk?: W): Promise<void>;
+    write(chunk: W): Promise<void>;
 }
 
 declare var WritableStreamDefaultWriter: {
diff --git a/baselines/ts5.6/dom.generated.d.ts b/baselines/ts5.6/dom.generated.d.ts
index 33b4c8b54..628f2f92d 100644
--- a/baselines/ts5.6/dom.generated.d.ts
+++ b/baselines/ts5.6/dom.generated.d.ts
@@ -37247,7 +37247,7 @@ interface TransformStreamDefaultController<O = any> {
      *
      * [MDN Reference](https://developer.mozilla.org/docs/Web/API/TransformStreamDefaultController/enqueue)
      */
-    enqueue(chunk?: O): void;
+    enqueue(chunk: O): void;
     /**
      * The **`error()`** method of the TransformStreamDefaultController interface errors both sides of the stream. Any further interactions with it will fail with the given error message, and any chunks in the queue will be discarded.
      *
@@ -42091,7 +42091,7 @@ interface WritableStreamDefaultWriter<W = any> {
      *
      * [MDN Reference](https://developer.mozilla.org/docs/Web/API/WritableStreamDefaultWriter/write)
      */
-    write(chunk?: W): Promise<void>;
+    write(chunk: W): Promise<void>;
 }
 
 declare var WritableStreamDefaultWriter: {
diff --git a/baselines/ts5.6/serviceworker.generated.d.ts b/baselines/ts5.6/serviceworker.generated.d.ts
index 9d420a826..ae05b3ddf 100644
--- a/baselines/ts5.6/serviceworker.generated.d.ts
+++ b/baselines/ts5.6/serviceworker.generated.d.ts
@@ -9310,7 +9310,7 @@ interface TransformStreamDefaultController<O = any> {
      *
      * [MDN Reference](https://developer.mozilla.org/docs/Web/API/TransformStreamDefaultController/enqueue)
      */
-    enqueue(chunk?: O): void;
+    enqueue(chunk: O): void;
     /**
      * The **`error()`** method of the TransformStreamDefaultController interface errors both sides of the stream. Any further interactions with it will fail with the given error message, and any chunks in the queue will be discarded.
      *
@@ -12763,7 +12763,7 @@ interface WritableStreamDefaultWriter<W = any> {
      *
      * [MDN Reference](https://developer.mozilla.org/docs/Web/API/WritableStreamDefaultWriter/write)
      */
-    write(chunk?: W): Promise<void>;
+    write(chunk: W): Promise<void>;
 }
 
 declare var WritableStreamDefaultWriter: {
diff --git a/baselines/ts5.6/sharedworker.generated.d.ts b/baselines/ts5.6/sharedworker.generated.d.ts
index 72b0b45ae..227dc54d1 100644
--- a/baselines/ts5.6/sharedworker.generated.d.ts
+++ b/baselines/ts5.6/sharedworker.generated.d.ts
@@ -8841,7 +8841,7 @@ interface TransformStreamDefaultController<O = any> {
      *
      * [MDN Reference](https://developer.mozilla.org/docs/Web/API/TransformStreamDefaultController/enqueue)
      */
-    enqueue(chunk?: O): void;
+    enqueue(chunk: O): void;
     /**
      * The **`error()`** method of the TransformStreamDefaultController interface errors both sides of the stream. Any further interactions with it will fail with the given error message, and any chunks in the queue will be discarded.
      *
@@ -12302,7 +12302,7 @@ interface WritableStreamDefaultWriter<W = any> {
      *
      * [MDN Reference](https://developer.mozilla.org/docs/Web/API/WritableStreamDefaultWriter/write)
      */
-    write(chunk?: W): Promise<void>;
+    write(chunk: W): Promise<void>;
 }
 
 declare var WritableStreamDefaultWriter: {
diff --git a/baselines/ts5.6/webworker.generated.d.ts b/baselines/ts5.6/webworker.generated.d.ts
index 092fb7a1b..3298efb4c 100644
--- a/baselines/ts5.6/webworker.generated.d.ts
+++ b/baselines/ts5.6/webworker.generated.d.ts
@@ -10468,7 +10468,7 @@ interface TransformStreamDefaultController<O = any> {
      *
      * [MDN Reference](https://developer.mozilla.org/docs/Web/API/TransformStreamDefaultController/enqueue)
      */
-    enqueue(chunk?: O): void;
+    enqueue(chunk: O): void;
     /**
      * The **`error()`** method of the TransformStreamDefaultController interface errors both sides of the stream. Any further interactions with it will fail with the given error message, and any chunks in the queue will be discarded.
      *
@@ -14251,7 +14251,7 @@ interface WritableStreamDefaultWriter<W = any> {
      *
      * [MDN Reference](https://developer.mozilla.org/docs/Web/API/WritableStreamDefaultWriter/write)
      */
-    write(chunk?: W): Promise<void>;
+    write(chunk: W): Promise<void>;
 }
 
 declare var WritableStreamDefaultWriter: {
diff --git a/baselines/ts5.9/audioworklet.generated.d.ts b/baselines/ts5.9/audioworklet.generated.d.ts
index af701138c..303cc493c 100644
--- a/baselines/ts5.9/audioworklet.generated.d.ts
+++ b/baselines/ts5.9/audioworklet.generated.d.ts
@@ -1224,7 +1224,7 @@ interface TransformStreamDefaultController<O = any> {
      *
      * [MDN Reference](https://developer.mozilla.org/docs/Web/API/TransformStreamDefaultController/enqueue)
      */
-    enqueue(chunk?: O): void;
+    enqueue(chunk: O): void;
     /**
      * The **`error()`** method of the TransformStreamDefaultController interface errors both sides of the stream. Any further interactions with it will fail with the given error message, and any chunks in the queue will be discarded.
      *
@@ -1534,7 +1534,7 @@ interface WritableStreamDefaultWriter<W = any> {
      *
      * [MDN Reference](https://developer.mozilla.org/docs/Web/API/WritableStreamDefaultWriter/write)
      */
-    write(chunk?: W): Promise<void>;
+    write(chunk: W): Promise<void>;
 }
 
 declare var WritableStreamDefaultWriter: {
diff --git a/baselines/ts5.9/dom.generated.d.ts b/baselines/ts5.9/dom.generated.d.ts
index 10dd2758c..fca24b564 100644
--- a/baselines/ts5.9/dom.generated.d.ts
+++ b/baselines/ts5.9/dom.generated.d.ts
@@ -37247,7 +37247,7 @@ interface TransformStreamDefaultController<O = any> {
      *
      * [MDN Reference](https://developer.mozilla.org/docs/Web/API/TransformStreamDefaultController/enqueue)
      */
-    enqueue(chunk?: O): void;
+    enqueue(chunk: O): void;
     /**
      * The **`error()`** method of the TransformStreamDefaultController interface errors both sides of the stream. Any further interactions with it will fail with the given error message, and any chunks in the queue will be discarded.
      *
@@ -42091,7 +42091,7 @@ interface WritableStreamDefaultWriter<W = any> {
      *
      * [MDN Reference](https://developer.mozilla.org/docs/Web/API/WritableStreamDefaultWriter/write)
      */
-    write(chunk?: W): Promise<void>;
+    write(chunk: W): Promise<void>;
 }
 
 declare var WritableStreamDefaultWriter: {
diff --git a/baselines/ts5.9/serviceworker.generated.d.ts b/baselines/ts5.9/serviceworker.generated.d.ts
index 3785996a6..138cf77bd 100644
--- a/baselines/ts5.9/serviceworker.generated.d.ts
+++ b/baselines/ts5.9/serviceworker.generated.d.ts
@@ -9310,7 +9310,7 @@ interface TransformStreamDefaultController<O = any> {
      *
      * [MDN Reference](https://developer.mozilla.org/docs/Web/API/TransformStreamDefaultController/enqueue)
      */
-    enqueue(chunk?: O): void;
+    enqueue(chunk: O): void;
     /**
      * The **`error()`** method of the TransformStreamDefaultController interface errors both sides of the stream. Any further interactions with it will fail with the given error message, and any chunks in the queue will be discarded.
      *
@@ -12763,7 +12763,7 @@ interface WritableStreamDefaultWriter<W = any> {
      *
      * [MDN Reference](https://developer.mozilla.org/docs/Web/API/WritableStreamDefaultWriter/write)
      */
-    write(chunk?: W): Promise<void>;
+    write(chunk: W): Promise<void>;
 }
 
 declare var WritableStreamDefaultWriter: {
diff --git a/baselines/ts5.9/sharedworker.generated.d.ts b/baselines/ts5.9/sharedworker.generated.d.ts
index a447ef65a..281c12ff4 100644
--- a/baselines/ts5.9/sharedworker.generated.d.ts
+++ b/baselines/ts5.9/sharedworker.generated.d.ts
@@ -8841,7 +8841,7 @@ interface TransformStreamDefaultController<O = any> {
      *
      * [MDN Reference](https://developer.mozilla.org/docs/Web/API/TransformStreamDefaultController/enqueue)
      */
-    enqueue(chunk?: O): void;
+    enqueue(chunk: O): void;
     /**
      * The **`error()`** method of the TransformStreamDefaultController interface errors both sides of the stream. Any further interactions with it will fail with the given error message, and any chunks in the queue will be discarded.
      *
@@ -12302,7 +12302,7 @@ interface WritableStreamDefaultWriter<W = any> {
      *
      * [MDN Reference](https://developer.mozilla.org/docs/Web/API/WritableStreamDefaultWriter/write)
      */
-    write(chunk?: W): Promise<void>;
+    write(chunk: W): Promise<void>;
 }
 
 declare var WritableStreamDefaultWriter: {
diff --git a/baselines/ts5.9/webworker.generated.d.ts b/baselines/ts5.9/webworker.generated.d.ts
index 308626981..f72c42764 100644
--- a/baselines/ts5.9/webworker.generated.d.ts
+++ b/baselines/ts5.9/webworker.generated.d.ts
@@ -10468,7 +10468,7 @@ interface TransformStreamDefaultController<O = any> {
      *
      * [MDN Reference](https://developer.mozilla.org/docs/Web/API/TransformStreamDefaultController/enqueue)
      */
-    enqueue(chunk?: O): void;
+    enqueue(chunk: O): void;
     /**
      * The **`error()`** method of the TransformStreamDefaultController interface errors both sides of the stream. Any further interactions with it will fail with the given error message, and any chunks in the queue will be discarded.
      *
@@ -14251,7 +14251,7 @@ interface WritableStreamDefaultWriter<W = any> {
      *
      * [MDN Reference](https://developer.mozilla.org/docs/Web/API/WritableStreamDefaultWriter/write)
      */
-    write(chunk?: W): Promise<void>;
+    write(chunk: W): Promise<void>;
 }
 
 declare var WritableStreamDefaultWriter: {
diff --git a/baselines/webworker.generated.d.ts b/baselines/webworker.generated.d.ts
index 293996edb..66b300868 100644
--- a/baselines/webworker.generated.d.ts
+++ b/baselines/webworker.generated.d.ts
@@ -10471,7 +10471,7 @@ interface TransformStreamDefaultController<O = any> {
      *
      * [MDN Reference](https://developer.mozilla.org/docs/Web/API/TransformStreamDefaultController/enqueue)
      */
-    enqueue(chunk?: O): void;
+    enqueue(chunk: O): void;
     /**
      * The **`error()`** method of the TransformStreamDefaultController interface errors both sides of the stream. Any further interactions with it will fail with the given error message, and any chunks in the queue will be discarded.
      *
@@ -14254,7 +14254,7 @@ interface WritableStreamDefaultWriter<W = any> {
      *
      * [MDN Reference](https://developer.mozilla.org/docs/Web/API/WritableStreamDefaultWriter/write)
      */
-    write(chunk?: W): Promise<void>;
+    write(chunk: W): Promise<void>;
 }
 
 declare var WritableStreamDefaultWriter: {
diff --git a/inputfiles/overridingTypes.jsonc b/inputfiles/overridingTypes.jsonc
index 7e53cf2e5..c6e2832d5 100644
--- a/inputfiles/overridingTypes.jsonc
+++ b/inputfiles/overridingTypes.jsonc
@@ -2323,6 +2323,7 @@
                                     "param": [
                                         {
                                             "name": "chunk",
+                                            "optional": false,
                                             "overrideType": "W"
                                         }
                                     ]
@@ -2408,6 +2409,7 @@
                                     "param": [
                                         {
                                             "name": "chunk",
+                                            "optional": false,
                                             "overrideType": "O"
                                         }
                                     ]