diff --git a/Gemfile.lock b/Gemfile.lock
index 1da8a68e6..de5569be0 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -22,7 +22,7 @@ GIT
 PATH
   remote: .
   specs:
-    rbs (4.1.2)
+    rbs (4.2.0.dev)
       logger
       prism (>= 1.6.0)
       tsort
diff --git a/lib/rbs/version.rb b/lib/rbs/version.rb
index 243f184d5..db11861cd 100644
--- a/lib/rbs/version.rb
+++ b/lib/rbs/version.rb
@@ -1,5 +1,5 @@
 # frozen_string_literal: true
 
 module RBS
-  VERSION = "4.1.2"
+  VERSION = "4.2.0.dev"
 end