diff --git a/Gemfile.lock b/Gemfile.lock
index 8eda27963..d0019f3c3 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,6 +1,6 @@
 GIT
   remote: https://github.com/soutaro/steep.git
-  revision: 35bb7dc667a709d999105fe78b534b819afef6d7
+  revision: 243debe385caaa96040f7cd7e750a00c5502ea60
   specs:
     steep (2.1.0.dev.1)
       concurrent-ruby (>= 1.1.10)
@@ -107,7 +107,7 @@ GEM
     parser (3.3.12.0)
       ast (~> 2.4.1)
       racc
-    power_assert (3.0.1)
+    power_assert (3.1.0)
     pp (0.6.4)
       prettyprint
     prettyprint (0.2.0)
diff --git a/steep/Gemfile.lock b/steep/Gemfile.lock
index 59d210544..78348da58 100644
--- a/steep/Gemfile.lock
+++ b/steep/Gemfile.lock
@@ -39,7 +39,7 @@ GEM
     parser (3.3.12.0)
       ast (~> 2.4.1)
       racc
-    power_assert (3.0.1)
+    power_assert (3.1.0)
     prism (1.9.0)
     racc (1.8.1)
     rainbow (3.1.1)
diff --git a/test/stdlib/Ripper_test.rb b/test/stdlib/Ripper_test.rb
index 257f5de7b..a27204ad5 100644
--- a/test/stdlib/Ripper_test.rb
+++ b/test/stdlib/Ripper_test.rb
@@ -1,4 +1,5 @@
 require_relative "test_helper"
+require "ripper"
 
 class RipperSingletonTest < Test::Unit::TestCase
   include TestHelper