diff --git a/app/services/manager.rb b/app/services/manager.rb
index 253560b..8e646b3 100644
--- a/app/services/manager.rb
+++ b/app/services/manager.rb
@@ -31,14 +31,14 @@ module DiscourseChat
         if topic.category # Also load the rules for the wildcard category
           matching_rules += DiscourseChat::Rule.with_type('normal').with_category_id(nil)
         end
-      end
 
-      # If groups are mentioned, check for any matching rules and append them
-      mentions = post.raw_mentions
-      if mentions && mentions.length > 0
-        groups = Group.where('LOWER(name) IN (?)', mentions)
-        if groups.exists?
-          matching_rules += DiscourseChat::Rule.with_type('group_mention').with_group_ids(groups.map(&:id))
+        # If groups are mentioned, check for any matching rules and append them
+        mentions = post.raw_mentions
+        if mentions && mentions.length > 0
+          groups = Group.where('LOWER(name) IN (?)', mentions)
+          if groups.exists?
+            matching_rules += DiscourseChat::Rule.with_type('group_mention').with_group_ids(groups.map(&:id))
+          end
         end
       end
 
diff --git a/spec/services/manager_spec.rb b/spec/services/manager_spec.rb
index bd75d55..23a4e2f 100644
--- a/spec/services/manager_spec.rb
+++ b/spec/services/manager_spec.rb
@@ -7,6 +7,7 @@ RSpec.describe DiscourseChat::Manager do
   let(:manager) { ::DiscourseChat::Manager }
   let(:category) { Fabricate(:category) }
   let(:group) { Fabricate(:group) }
+  let(:group2) { Fabricate(:group) }
   let(:topic) { Fabricate(:topic, category_id: category.id) }
   let(:first_post) { Fabricate(:post, topic: topic) }
   let(:second_post) { Fabricate(:post, topic: topic, post_number: 2) }
@@ -121,7 +122,6 @@ RSpec.describe DiscourseChat::Manager do
     end
 
     it "should work for pms with multiple groups" do
-      group2 = Fabricate(:group)
       DiscourseChat::Rule.create!(channel: chan1, type: 'group_message', filter: 'watch', group_id: group.id)
       DiscourseChat::Rule.create!(channel: chan2, type: 'group_message', filter: 'watch', group_id: group2.id)
 
@@ -145,8 +145,6 @@ RSpec.describe DiscourseChat::Manager do
       expect(provider.sent_to_channel_ids).to contain_exactly(chan1.id, chan3.id)
     end
 
-    
-
     it "should give group rule precedence over normal rules" do
       third_post = Fabricate(:post, topic: topic, post_number: 3, raw: "let's mention @#{group.name}")
 
@@ -159,6 +157,24 @@ RSpec.describe DiscourseChat::Manager do
       expect(provider.sent_to_channel_ids).to contain_exactly(chan1.id)
     end
 
+    it "should not notify about mentions in private messages" do
+      # Group 1 watching for messages on channel 1
+      DiscourseChat::Rule.create!(channel: chan1, filter: 'watch', type: 'group_message', group_id: group.id)
+      # Group 2 watching for mentions on channel 2
+      DiscourseChat::Rule.create!(channel: chan2, filter: 'watch', type: 'group_mention', group_id: group2.id)
+
+      # Make a private message only accessible to group 1
+      private_message = Fabricate(:private_message_post)
+      private_message.topic.invite_group(Fabricate(:user), group)
+
+      # Mention group 2 in the message
+      mention_post = Fabricate(:post, topic: private_message.topic, post_number: 2, raw: "let's mention @#{group2.name}")
+
+      # We expect that only group 1 receives a notification
+      manager.trigger_notifications(mention_post.id)
+      expect(provider.sent_to_channel_ids).to contain_exactly(chan1.id)
+    end
+
     it "should not notify about posts the chat_user cannot see" do
       DiscourseChat::Rule.create!(channel: chan1, filter: 'follow', category_id: nil) # Wildcard watch