diff --git a/src/vs/workbench/api/common/extHost.protocol.ts b/src/vs/workbench/api/common/extHost.protocol.ts
index cbcfd9c0720..4e2f83f5fcc 100644
--- a/src/vs/workbench/api/common/extHost.protocol.ts
+++ b/src/vs/workbench/api/common/extHost.protocol.ts
@@ -536,7 +536,7 @@ export interface MainThreadTerminalServiceShape extends IDisposable {
 }
 
 export type TransferQuickPickItemOrSeparator = TransferQuickPickItem | quickInput.IQuickPickSeparator;
-export interface TransferQuickPickItem extends Dto<quickInput.IQuickPickItem> {
+export interface TransferQuickPickItem extends quickInput.IQuickPickItem {
 	handle: number;
 	buttons?: TransferQuickInputButton[];
 }
@@ -2176,7 +2176,7 @@ export interface ExtHostTestingShape {
 	/** Handles a diff of tests, as a result of a subscribeToDiffs() call */
 	$acceptDiff(diff: TestsDiff): void;
 	/** Publishes that a test run finished. */
-	$publishTestResults(results: Dto<ISerializedTestResults[]>): void;
+	$publishTestResults(results: ISerializedTestResults[]): void;
 	/** Expands a test item's children, by the given number of levels. */
 	$expandTest(testId: string, levels: number): Promise<void>;
 	/** Requests file coverage for a test run. Errors if not available. */
diff --git a/src/vs/workbench/services/extensions/common/proxyIdentifier.ts b/src/vs/workbench/services/extensions/common/proxyIdentifier.ts
index 3880c906495..f41429e338a 100644
--- a/src/vs/workbench/services/extensions/common/proxyIdentifier.ts
+++ b/src/vs/workbench/services/extensions/common/proxyIdentifier.ts
@@ -64,12 +64,8 @@ export type Dto<T> = T extends { toJSON(): infer U }
 	? { [k in keyof T]: Dto<T[k]>; }
 	: T;
 
-/**
- * Map `T` to be only functions that return promises of data transfer objects and that
- * accept arguments of data transfer objects.
- */
 export type Proxied<T> = { [K in keyof T]: T[K] extends (...args: infer A) => infer R
-	? (...args: { [K in keyof A]: Dto<A[K]> }) => Promise<Dto<Awaited<R>>>
+	? (...args: A) => Promise<Dto<Awaited<R>>>
 	: never
 };