diff --git a/src/vs/workbench/api/common/extHost.api.impl.ts b/src/vs/workbench/api/common/extHost.api.impl.ts
index 7766c78231f..789d30aec57 100644
--- a/src/vs/workbench/api/common/extHost.api.impl.ts
+++ b/src/vs/workbench/api/common/extHost.api.impl.ts
@@ -1454,7 +1454,7 @@ export function createApiFactoryAndRegisterActors(accessor: ServicesAccessor): I
 				return extHostChatAgents2.createDynamicChatAgent(extension, id, dynamicProps, handler);
 			},
 			registerChatParticipantDetectionProvider(provider: vscode.ChatParticipantDetectionProvider) {
-				checkProposedApiEnabled(extension, 'chatParticipantAdditions');
+				checkProposedApiEnabled(extension, 'chatParticipantPrivate');
 				return extHostChatAgents2.registerChatParticipantDetectionProvider(extension, provider);
 			},
 			registerRelatedFilesProvider(provider: vscode.ChatRelatedFilesProvider, metadata: vscode.ChatRelatedFilesProviderMetadata) {
diff --git a/src/vscode-dts/vscode.proposed.chatParticipantAdditions.d.ts b/src/vscode-dts/vscode.proposed.chatParticipantAdditions.d.ts
index 814274a48dd..ed5da524cea 100644
--- a/src/vscode-dts/vscode.proposed.chatParticipantAdditions.d.ts
+++ b/src/vscode-dts/vscode.proposed.chatParticipantAdditions.d.ts
@@ -278,23 +278,6 @@ declare module 'vscode' {
 		 * Create a chat participant with the extended progress type
 		 */
 		export function createChatParticipant(id: string, handler: ChatExtendedRequestHandler): ChatParticipant;
-
-		export function registerChatParticipantDetectionProvider(participantDetectionProvider: ChatParticipantDetectionProvider): Disposable;
-	}
-
-	export interface ChatParticipantMetadata {
-		participant: string;
-		command?: string;
-		disambiguation: { category: string; description: string; examples: string[] }[];
-	}
-
-	export interface ChatParticipantDetectionResult {
-		participant: string;
-		command?: string;
-	}
-
-	export interface ChatParticipantDetectionProvider {
-		provideParticipantDetection(chatRequest: ChatRequest, context: ChatContext, options: { participants?: ChatParticipantMetadata[]; location: ChatLocation }, token: CancellationToken): ProviderResult<ChatParticipantDetectionResult>;
 	}
 
 	/*
diff --git a/src/vscode-dts/vscode.proposed.chatParticipantPrivate.d.ts b/src/vscode-dts/vscode.proposed.chatParticipantPrivate.d.ts
index 10a4ce36ce5..b5b7c170df3 100644
--- a/src/vscode-dts/vscode.proposed.chatParticipantPrivate.d.ts
+++ b/src/vscode-dts/vscode.proposed.chatParticipantPrivate.d.ts
@@ -127,4 +127,23 @@ declare module 'vscode' {
 		pastTenseMessage?: string | MarkdownString;
 		tooltip?: string | MarkdownString;
 	}
+
+	export interface ChatParticipantMetadata {
+		participant: string;
+		command?: string;
+		disambiguation: { category: string; description: string; examples: string[] }[];
+	}
+
+	export interface ChatParticipantDetectionResult {
+		participant: string;
+		command?: string;
+	}
+
+	export interface ChatParticipantDetectionProvider {
+		provideParticipantDetection(chatRequest: ChatRequest, context: ChatContext, options: { participants?: ChatParticipantMetadata[]; location: ChatLocation }, token: CancellationToken): ProviderResult<ChatParticipantDetectionResult>;
+	}
+
+	export namespace chat {
+		export function registerChatParticipantDetectionProvider(participantDetectionProvider: ChatParticipantDetectionProvider): Disposable;
+	}
 }