diff --git a/spec/components/plugin/instance_spec.rb b/spec/components/plugin/instance_spec.rb
index df5fba1ec..4cc5ab03c 100644
--- a/spec/components/plugin/instance_spec.rb
+++ b/spec/components/plugin/instance_spec.rb
@@ -49,7 +49,7 @@ describe Plugin::Instance do
         # DiscourseEvent
         @hello_count = 0
         @increase_count = -> { @hello_count += 1 }
-        @plugin.on(:hello, &@increase_count)
+        @set = @plugin.on(:hello, &@increase_count)
 
         # Serializer
         @plugin.add_to_serializer(:trout, :scales) { 1024 }
@@ -57,7 +57,7 @@ describe Plugin::Instance do
       end
 
       after do
-        DiscourseEvent.off(:hello, &@increase_count)
+        DiscourseEvent.off(:hello, &@set.last)
       end
 
       it "checks enabled/disabled functionality for extensions" do