diff --git a/tildes/tests/test_comment_user_mentions.py b/tildes/tests/test_comment_user_mentions.py
index b019b63..eacbc52 100644
--- a/tildes/tests/test_comment_user_mentions.py
+++ b/tildes/tests/test_comment_user_mentions.py
@@ -36,15 +36,10 @@ def test_get_mentions_for_comment(db, user_list, comment):
         assert mentions[index].user == user
 
 
-def test_mention_filtering_parent_comment(mocker, db, topic, user_list):
+def test_mention_filtering_parent_comment(db, topic, user_list):
     """Test notification filtering for parent comments."""
     parent_comment = Comment(topic, user_list[0], "Comment content.")
-    parent_comment.user_id = user_list[0].user_id
-    comment = mocker.Mock(
-        user_id=user_list[1].user_id,
-        markdown=f"@{user_list[0].username}",
-        parent_comment=parent_comment,
-    )
+    comment = Comment(topic, user_list[1], f"@{user_list[0].username}", parent_comment)
     mentions = CommentNotification.get_mentions_for_comment(db, comment)
     assert not mentions
 
diff --git a/tildes/tildes/models/comment/comment.py b/tildes/tildes/models/comment/comment.py
index 872a0e3..9701bed 100644
--- a/tildes/tildes/models/comment/comment.py
+++ b/tildes/tildes/models/comment/comment.py
@@ -5,7 +5,7 @@
 
 from collections import Counter
 from datetime import datetime, timedelta
-from typing import Any, Optional, Sequence, Tuple, TYPE_CHECKING
+from typing import Any, Optional, Sequence, Tuple, TYPE_CHECKING, Union
 
 from pyramid.security import Allow, Authenticated, Deny, DENY_ALL, Everyone
 from sqlalchemy import Boolean, Column, ForeignKey, Integer, Text, TIMESTAMP
@@ -228,6 +228,14 @@ class Comment(DatabaseModel):
         """Return the comment's ID in ID36 format."""
         return id_to_id36(self.comment_id)
 
+    @property
+    def parent(self) -> Union["Comment", Topic]:
+        """Return what the comment is replying to (a topic or another comment)."""
+        if self.parent_comment:
+            return self.parent_comment
+
+        return self.topic
+
     @property
     def parent_comment_id36(self) -> str:
         """Return the parent comment's ID in ID36 format."""
diff --git a/tildes/tildes/models/comment/comment_notification.py b/tildes/tildes/models/comment/comment_notification.py
index 68c34de..162c5aa 100644
--- a/tildes/tildes/models/comment/comment_notification.py
+++ b/tildes/tildes/models/comment/comment_notification.py
@@ -55,6 +55,12 @@ class CommentNotification(DatabaseModel):
         self, user: User, comment: Comment, notification_type: CommentNotificationType
     ):
         """Create a new notification for a user from a comment."""
+        if notification_type in (
+            CommentNotificationType.COMMENT_REPLY,
+            CommentNotificationType.TOPIC_REPLY,
+        ) and not self.should_create_reply_notification(comment):
+            raise ValueError("That comment shouldn't create a reply notification")
+
         self.user = user
         self.comment = comment
         self.notification_type = notification_type
@@ -66,6 +72,18 @@ class CommentNotification(DatabaseModel):
         acl.append(DENY_ALL)
         return acl
 
+    @classmethod
+    def should_create_reply_notification(cls, comment: Comment) -> bool:
+        """Return whether a comment should generate a reply notification."""
+        # User is replying to their own post
+        if comment.parent.user == comment.user:
+            return False
+
+        if not comment.parent.user.is_real_user:
+            return False
+
+        return True
+
     @property
     def is_comment_reply(self) -> bool:
         """Return whether this is a comment reply notification."""
@@ -95,19 +113,14 @@ class CommentNotification(DatabaseModel):
             .all()
         )
 
-        parent_comment = comment.parent_comment
-
         for user in users_to_mention:
             # prevent the user from mentioning themselves
             if comment.user == user:
                 continue
 
-            if parent_comment:
-                # prevent comment replies from mentioning that comment's poster
-                if parent_comment.user == user:
-                    continue
-            # prevent top-level comments from mentioning the thread creator
-            elif comment.topic.user == user:
+            # prevent mentioning the user they're replying to
+            # (they'll already get a reply notification)
+            if comment.parent.user == user:
                 continue
 
             mention_notification = cls(
diff --git a/tildes/tildes/views/api/web/comment.py b/tildes/tildes/views/api/web/comment.py
index 8d300e0..903bffc 100644
--- a/tildes/tildes/views/api/web/comment.py
+++ b/tildes/tildes/views/api/web/comment.py
@@ -95,7 +95,7 @@ def post_toplevel_comment(request: Request, markdown: str) -> dict:
 
     request.db_session.add(LogComment(LogEventType.COMMENT_POST, request, new_comment))
 
-    if topic.user != request.user and not topic.is_deleted:
+    if CommentNotification.should_create_reply_notification(new_comment):
         notification = CommentNotification(
             topic.user, new_comment, CommentNotificationType.TOPIC_REPLY
         )
@@ -135,7 +135,7 @@ def post_comment_reply(request: Request, markdown: str) -> dict:
 
     request.db_session.add(LogComment(LogEventType.COMMENT_POST, request, new_comment))
 
-    if parent_comment.user != request.user:
+    if CommentNotification.should_create_reply_notification(new_comment):
         notification = CommentNotification(
             parent_comment.user, new_comment, CommentNotificationType.COMMENT_REPLY
         )
diff --git a/tildes/tildes/views/topic.py b/tildes/tildes/views/topic.py
index af879b9..c21b021 100644
--- a/tildes/tildes/views/topic.py
+++ b/tildes/tildes/views/topic.py
@@ -415,7 +415,7 @@ def post_comment_on_topic(request: Request, markdown: str) -> HTTPFound:
 
     request.db_session.add(LogComment(LogEventType.COMMENT_POST, request, new_comment))
 
-    if topic.user != request.user and not topic.is_deleted:
+    if CommentNotification.should_create_reply_notification(new_comment):
         notification = CommentNotification(
             topic.user, new_comment, CommentNotificationType.TOPIC_REPLY
         )