diff --git a/tests/Tasks/UpdatePackageInfoTest.php b/tests/Tasks/UpdatePackageInfoTest.php
index 2319784..7b5a704 100644
--- a/tests/Tasks/UpdatePackageInfoTest.php
+++ b/tests/Tasks/UpdatePackageInfoTest.php
@@ -50,7 +50,7 @@ public function testPackagesAreAddedCorrectly()
 
         $frameworkVersion = VersionProvider::singleton()->getModuleVersion('silverstripe/framework');
         $composerLoader = $this->getMockBuilder(ComposerLoader::class)
-            ->setMethods(['getLock'])->getMock();
+            ->setMethods(['getLock', 'getPackages'])->getMock();
         $composerLoader->expects($this->any())->method('getLock')->will($this->returnValue(json_decode(<<<LOCK
 {
     "packages": [
@@ -69,6 +69,11 @@ public function testPackagesAreAddedCorrectly()
 }
 LOCK
         )));
+        // prevent extension CheckComposerUpdatesExtension::updatePackageInfo()
+        // in bringyourownideas/silverstripe-composer-update-checker
+        // from fetching data from github
+        $composerLoader->expects($this->any())->method('getPackages')->will($this->returnValue([]));
+
         $task->setComposerLoader($composerLoader);
 
         $task->run(null);