diff --git a/lib/twitter_ebooks/bot.rb b/lib/twitter_ebooks/bot.rb
index ed03229..f76c1d8 100644
--- a/lib/twitter_ebooks/bot.rb
+++ b/lib/twitter_ebooks/bot.rb
@@ -40,8 +40,8 @@ module Ebooks
     # Figure out whether to keep this user in the reply prefix
     # We want to avoid spamming non-participating users
     def can_include?(username)
-      @tweets.length <= 6 ||
-        !@tweets[-6..-1].select { |t| t.user.screen_name.downcase == username.downcase }.empty?
+      @tweets.length <= 4 ||
+        !@tweets.select { |t| t.user.screen_name.downcase == username.downcase }.empty?
     end
   end
 
diff --git a/spec/bot_spec.rb b/spec/bot_spec.rb
index 6468524..ba07a4d 100644
--- a/spec/bot_spec.rb
+++ b/spec/bot_spec.rb
@@ -134,11 +134,7 @@ describe Ebooks::Bot do
 
       Timecop.travel(Time.now + 60)
       bot.receive_event(mock_tweet("spammer", "@test_ebooks @m1sp 3"))
-      expect_tweet(bot, "@spammer @m1sp echo: 3")
-
-      Timecop.travel(Time.now + 60)
-      bot.receive_event(mock_tweet("spammer", "@test_ebooks @m1sp 4"))
-      expect_tweet(bot, "@spammer echo: 4")
+      expect_tweet(bot, "@spammer echo: 3")
     end
   end