diff --git a/forum/__init__.py b/forum/__init__.py
index 186652c8..5084d37a 100644
--- a/forum/__init__.py
+++ b/forum/__init__.py
@@ -2,4 +2,4 @@
 Openedx forum app.
 """
 
-__version__ = "0.6.8"
+__version__ = "0.6.9"
diff --git a/forum/api/users.py b/forum/api/users.py
index fbe5608b..ded86e8b 100644
--- a/forum/api/users.py
+++ b/forum/api/users.py
@@ -303,11 +303,10 @@ def _get_stats_for_usernames(
     course_id: str, usernames: list[str], backend: Any
 ) -> list[dict[str, Any]]:
     """Get stats for specific usernames."""
-    users = backend.get_users()
+    users = backend.get_users(username__in=usernames)
+
     stats_query = []
     for user in users:
-        if user["username"] not in usernames:
-            continue
         course_stats = user.get("course_stats")
         if course_stats:
             for course_stat in course_stats:
diff --git a/forum/backends/mongodb/api.py b/forum/backends/mongodb/api.py
index 4f33b9a4..41c3e922 100644
--- a/forum/backends/mongodb/api.py
+++ b/forum/backends/mongodb/api.py
@@ -1995,6 +1995,10 @@ def get_course_id_by_comment_id(comment_id: str) -> str | None:
     @staticmethod
     def get_users(**kwargs: Any) -> list[dict[str, Any]]:
         """Get users."""
+        kwargs = kwargs.copy()
+        username_in = kwargs.pop("username__in", None)
+        if username_in is not None:
+            kwargs["username"] = {"$in": username_in}
         return list(Users().get_list(**kwargs))
 
     @staticmethod
diff --git a/forum/backends/mysql/api.py b/forum/backends/mysql/api.py
index 49be84b8..4ccdd1ac 100644
--- a/forum/backends/mysql/api.py
+++ b/forum/backends/mysql/api.py
@@ -2606,8 +2606,13 @@ def get_users(**kwargs: Any) -> list[dict[str, Any]]:
         Returns:
             A list of users.
         """
+        kwargs = kwargs.copy()
+        sort_key = kwargs.pop("sort_key", None)
+        username_in = kwargs.pop("username__in", None)
+        if username_in is not None:
+            kwargs["user__username__in"] = username_in
+
         forum_users = ForumUser.objects.filter(**kwargs)
-        sort_key = kwargs.get("sort_key")
         if sort_key:
             forum_users = forum_users.order_by(sort_key)