diff --git a/lib/irb/irb.gemspec b/lib/irb/irb.gemspec
index c910bbb5c5..658fe813f1 100644
--- a/lib/irb/irb.gemspec
+++ b/lib/irb/irb.gemspec
@@ -39,6 +39,7 @@ Gem::Specification.new do |spec|
     "lib/irb/color.rb",
     "lib/irb/completion.rb",
     "lib/irb/context.rb",
+    "lib/irb/easter-egg.rb",
     "lib/irb/ext/change-ws.rb",
     "lib/irb/ext/history.rb",
     "lib/irb/ext/loader.rb",