diff --git a/patches/custom-extensions-gallery.patch b/patches/custom-extensions-gallery.patch
new file mode 100644
index 0000000..2d4f4ec
--- /dev/null
+++ b/patches/custom-extensions-gallery.patch
@@ -0,0 +1,28 @@
+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
+ 	});
diff --git a/prepare_vscode.sh b/prepare_vscode.sh
index a4cbe46..7995670 100755
--- a/prepare_vscode.sh
+++ b/prepare_vscode.sh
@@ -8,6 +8,7 @@ cd vscode || exit
 ../update_settings.sh
 
 # apply patches
+patch -u src/vs/platform/product/common/product.ts -i ../patches/custom-extensions-gallery.patch
 patch -u src/vs/platform/update/electron-main/updateService.win32.ts -i ../patches/update-cache-path.patch
 patch -u resources/linux/rpm/code.spec.template -i ../patches/fix-rpm-spec.patch