diff --git a/src/vs/workbench/contrib/chat/browser/widget/chatContentParts/chatThinkingContentPart.ts b/src/vs/workbench/contrib/chat/browser/widget/chatContentParts/chatThinkingContentPart.ts
index 4f926a701d4..e3ddd1312ad 100644
--- a/src/vs/workbench/contrib/chat/browser/widget/chatContentParts/chatThinkingContentPart.ts
+++ b/src/vs/workbench/contrib/chat/browser/widget/chatContentParts/chatThinkingContentPart.ts
@@ -718,10 +718,7 @@ export class ChatThinkingContentPart extends ChatCollapsibleContentPart implemen
 		const timeout = setTimeout(() => cts.cancel(), 5000);
 
 		try {
-			let models = await this.languageModelsService.selectLanguageModels({ vendor: 'copilot', id: 'copilot-fast' });
-			if (!models.length) {
-				models = await this.languageModelsService.selectLanguageModels({ vendor: 'copilot', family: 'gpt-4o-mini' });
-			}
+			const models = await this.languageModelsService.selectLanguageModels({ vendor: 'copilot', id: 'copilot-fast' });
 			if (!models.length) {
 				this.setFallbackTitle();
 				return;
diff --git a/src/vs/workbench/contrib/chat/browser/widget/input/chatInputPart.ts b/src/vs/workbench/contrib/chat/browser/widget/input/chatInputPart.ts
index b0fd053396d..518c735c5d3 100644
--- a/src/vs/workbench/contrib/chat/browser/widget/input/chatInputPart.ts
+++ b/src/vs/workbench/contrib/chat/browser/widget/input/chatInputPart.ts
@@ -665,7 +665,7 @@ export class ChatInputPart extends Disposable implements IHistoryNavigationWidge
 
 	private initSelectedModel() {
 		const persistedSelection = this.storageService.get(this.getSelectedModelStorageKey(), StorageScope.APPLICATION);
-		const persistedAsDefault = this.storageService.getBoolean(this.getSelectedModelIsDefaultStorageKey(), StorageScope.APPLICATION, persistedSelection === 'copilot/gpt-4.1');
+		const persistedAsDefault = this.storageService.getBoolean(this.getSelectedModelIsDefaultStorageKey(), StorageScope.APPLICATION, true);
 
 		if (persistedSelection) {
 			const model = this.getModels().find(m => m.identifier === persistedSelection);
diff --git a/src/vs/workbench/contrib/terminalContrib/chatAgentTools/browser/tools/monitoring/outputMonitor.ts b/src/vs/workbench/contrib/terminalContrib/chatAgentTools/browser/tools/monitoring/outputMonitor.ts
index 8c70eb496af..081534d5031 100644
--- a/src/vs/workbench/contrib/terminalContrib/chatAgentTools/browser/tools/monitoring/outputMonitor.ts
+++ b/src/vs/workbench/contrib/terminalContrib/chatAgentTools/browser/tools/monitoring/outputMonitor.ts
@@ -877,13 +877,7 @@ export class OutputMonitor extends Disposable implements IOutputMonitor {
 	}
 
 	private async _getLanguageModel(): Promise<string | undefined> {
-		let models = await this._languageModelsService.selectLanguageModels({ vendor: 'copilot', id: 'copilot-fast' });
-
-		// Fallback to gpt-4o-mini if copilot-fast is not available for backwards compatibility
-		if (!models.length) {
-			models = await this._languageModelsService.selectLanguageModels({ vendor: 'copilot', family: 'gpt-4o-mini' });
-		}
-
+		const models = await this._languageModelsService.selectLanguageModels({ vendor: 'copilot', id: 'copilot-fast' });
 		return models.length ? models[0] : undefined;
 	}
 }