diff --git a/SilMock/Google/Service/Directory/Resource/Groups.php b/SilMock/Google/Service/Directory/Resource/Groups.php
index 31dd654..b97b549 100644
--- a/SilMock/Google/Service/Directory/Resource/Groups.php
+++ b/SilMock/Google/Service/Directory/Resource/Groups.php
@@ -116,6 +116,15 @@ public function listGroups($optParams = []): GoogleDirectory_Groups
         if (0 < $currentResultSize && $currentResultSize <= $pageSize) {
             $groups->setNextPageToken(sprintf("%d", $pageToken + 1));
         }
+        // Thankfully, setting the aliases in the loop
+        // fixes the empty aliases in groups.
+        foreach ($groups->getGroups() as $group) {
+            $mockGroupsAliasesObject = new GroupsAliases($this->dbFile);
+            $aliasesObject = $mockGroupsAliasesObject->listGroupsAliases($group->getEmail());
+            $aliasesObjectArray = $aliasesObject->getAliases();
+            $aliases = array_map(function (GoogleDirectory_GroupAlias $alias) { return $alias->getAlias(); }, $aliasesObjectArray);
+            $group->setAliases($aliases);
+        }
         return $groups;
     }
 
diff --git a/composer.json b/composer.json
index 9fc069b..97c379e 100644
--- a/composer.json
+++ b/composer.json
@@ -1,6 +1,6 @@
 {
     "name": "silinternational/google-api-php-client-mock",
-    "version": "2.13.0",
+    "version": "2.13.1",
     "description": "Attempting to create an intelligent mock of the Google API PHP Client for unit and functional testing.",
     "type": "library",
     "keywords": [
diff --git a/composer.lock b/composer.lock
index 0093d28..9258af0 100644
--- a/composer.lock
+++ b/composer.lock
@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "08c15db16ea28b2055642d25c855bc2f",
+    "content-hash": "98589aa7e195a743dcf2387f4ae0d570",
     "packages": [
         {
             "name": "firebase/php-jwt",