diff --git a/src/vs/platform/product/common/product.ts b/src/vs/platform/product/common/product.ts
index 2bea85740c..d0e9da036c 100644
--- a/src/vs/platform/product/common/product.ts
+++ b/src/vs/platform/product/common/product.ts
@@ -57,6 +57,23 @@ else {
 		});
 	}
 
+	// Set user-defined extension gallery
+	if (
+		env['VSCODIUM_EXTENSIONS_GALLERY_SERVICE_URL']
+		|| env['VSCODIUM_EXTENSIONS_GALLERY_ITEM_URL']
+		|| env['VSCODIUM_EXTENSIONS_GALLERY_CONTROL_URL']
+		|| env['VSCODIUM_EXTENSIONS_GALLERY_RECOMMENDATIONS_URL']
+	) {
+		Object.assign(product, {
+			extensionsGallery: {
+				serviceUrl: env['VSCODIUM_EXTENSIONS_GALLERY_SERVICE_URL'],
+				itemUrl: env['VSCODIUM_EXTENSIONS_GALLERY_ITEM_URL'],
+				controlUrl: env['VSCODIUM_EXTENSIONS_GALLERY_CONTROL_URL'],
+				recommendationsUrl: env['VSCODIUM_EXTENSIONS_GALLERY_RECOMMENDATIONS_URL']
+			}
+		})
+	}
+
 	Object.assign(product, {
 		version: pkg.version
 	});