diff --git a/CHANGELOG.md b/CHANGELOG.md
index 618e281..0d31497 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,8 @@
 # Changelog
 
+## 3.3.0
+- Add unique constraint.
+
 ## 3.2.0
 - Add match constraint.
 - Fix the rollback of change view migrations.
diff --git a/gemfiles/activerecord_4.gemfile.lock b/gemfiles/activerecord_4.gemfile.lock
index c8296ec..e1bd1f4 100644
--- a/gemfiles/activerecord_4.gemfile.lock
+++ b/gemfiles/activerecord_4.gemfile.lock
@@ -1,7 +1,7 @@
 PATH
   remote: ..
   specs:
-    rein (3.2.0)
+    rein (3.3.0)
       activerecord (>= 4.0.0, < 6)
       activesupport (>= 4.0.0, < 6)
 
diff --git a/gemfiles/activerecord_5.gemfile.lock b/gemfiles/activerecord_5.gemfile.lock
index 749c00a..a824e50 100644
--- a/gemfiles/activerecord_5.gemfile.lock
+++ b/gemfiles/activerecord_5.gemfile.lock
@@ -1,7 +1,7 @@
 PATH
   remote: ..
   specs:
-    rein (3.2.0)
+    rein (3.3.0)
       activerecord (>= 4.0.0, < 6)
       activesupport (>= 4.0.0, < 6)
 
diff --git a/lib/rein/version.rb b/lib/rein/version.rb
index bc35704..c4acae0 100644
--- a/lib/rein/version.rb
+++ b/lib/rein/version.rb
@@ -1,3 +1,3 @@
 module Rein
-  VERSION = '3.2.0'.freeze
+  VERSION = '3.3.0'.freeze
 end