diff --git a/src/vs/workbench/contrib/extensions/browser/extensions.contribution.ts b/src/vs/workbench/contrib/extensions/browser/extensions.contribution.ts
index 6fbc52d18ba42..befa640deb2a7 100644
--- a/src/vs/workbench/contrib/extensions/browser/extensions.contribution.ts
+++ b/src/vs/workbench/contrib/extensions/browser/extensions.contribution.ts
@@ -227,7 +227,7 @@ Registry.as<IConfigurationRegistry>(ConfigurationExtensions.Configuration)
 			'extensions.experimental.useUtilityProcess': {
 				type: 'boolean',
 				description: localize('extensionsUseUtilityProcess', "When enabled, the extension host will be launched using the new UtilityProcess Electron API."),
-				default: true
+				default: false
 			},
 			[WORKSPACE_TRUST_EXTENSION_SUPPORT]: {
 				type: 'object',