diff --git a/lib/irb/irb.gemspec b/lib/irb/irb.gemspec
index af40a32452..aba3f15675 100644
--- a/lib/irb/irb.gemspec
+++ b/lib/irb/irb.gemspec
@@ -33,6 +33,7 @@ Gem::Specification.new do |spec|
     "lib/irb/cmd/fork.rb",
     "lib/irb/cmd/help.rb",
     "lib/irb/cmd/load.rb",
+    "lib/irb/cmd/measure.rb",
     "lib/irb/cmd/nop.rb",
     "lib/irb/cmd/pushws.rb",
     "lib/irb/cmd/subirb.rb",