diff --git a/RAILS_VERSION b/RAILS_VERSION
index fcdb2e109f68c..93f97c61ea640 100644
--- a/RAILS_VERSION
+++ b/RAILS_VERSION
@@ -1 +1 @@
-4.0.0
+4.0.1.rc1
diff --git a/actionmailer/lib/action_mailer/version.rb b/actionmailer/lib/action_mailer/version.rb
index caf05349e5e07..b2675f1685822 100644
--- a/actionmailer/lib/action_mailer/version.rb
+++ b/actionmailer/lib/action_mailer/version.rb
@@ -1,7 +1,7 @@
 module ActionMailer
   # Returns the version of the currently loaded ActionMailer as a Gem::Version
   def self.version
-    Gem::Version.new "4.0.0"
+    Gem::Version.new "4.0.1.rc1"
   end
 
   module VERSION #:nodoc:
diff --git a/actionpack/lib/action_pack/version.rb b/actionpack/lib/action_pack/version.rb
index c48b12b9b8fff..19a0ee7300f3b 100644
--- a/actionpack/lib/action_pack/version.rb
+++ b/actionpack/lib/action_pack/version.rb
@@ -1,7 +1,7 @@
 module ActionPack
   # Returns the version of the currently loaded ActionPack as a Gem::Version
   def self.version
-    Gem::Version.new "4.0.0"
+    Gem::Version.new "4.0.1.rc1"
   end
 
   module VERSION #:nodoc:
diff --git a/activemodel/lib/active_model/version.rb b/activemodel/lib/active_model/version.rb
index 4d0196455f766..c13247077bb87 100644
--- a/activemodel/lib/active_model/version.rb
+++ b/activemodel/lib/active_model/version.rb
@@ -1,7 +1,7 @@
 module ActiveModel
   # Returns the version of the currently loaded ActiveModel as a Gem::Version
   def self.version
-    Gem::Version.new "4.0.0"
+    Gem::Version.new "4.0.1.rc1"
   end
 
   module VERSION #:nodoc:
diff --git a/activerecord/lib/active_record/version.rb b/activerecord/lib/active_record/version.rb
index bb97bfcc821d4..c7eacd21696cb 100644
--- a/activerecord/lib/active_record/version.rb
+++ b/activerecord/lib/active_record/version.rb
@@ -1,7 +1,7 @@
 module ActiveRecord
   # Returns the version of the currently loaded ActiveRecord as a Gem::Version
   def self.version
-    Gem::Version.new "4.0.0"
+    Gem::Version.new "4.0.1.rc1"
   end
 
   module VERSION #:nodoc:
diff --git a/activesupport/lib/active_support/version.rb b/activesupport/lib/active_support/version.rb
index 66272d0e99e2b..3ec57839a8e64 100644
--- a/activesupport/lib/active_support/version.rb
+++ b/activesupport/lib/active_support/version.rb
@@ -1,7 +1,7 @@
 module ActiveSupport
   # Returns the version of the currently loaded ActiveSupport as a Gem::Version
   def self.version
-    Gem::Version.new "4.0.0"
+    Gem::Version.new "4.0.1.rc1"
   end
 
   module VERSION #:nodoc:
diff --git a/railties/lib/rails/version.rb b/railties/lib/rails/version.rb
index 180c9712a9678..03910daf793b3 100644
--- a/railties/lib/rails/version.rb
+++ b/railties/lib/rails/version.rb
@@ -2,8 +2,8 @@ module Rails
   module VERSION
     MAJOR = 4
     MINOR = 0
-    TINY  = 0
-    PRE   = nil
+    TINY  = 1
+    PRE   = "rc1"
 
     STRING = [MAJOR, MINOR, TINY, PRE].compact.join(".")
   end
diff --git a/version.rb b/version.rb
index 180c9712a9678..03910daf793b3 100644
--- a/version.rb
+++ b/version.rb
@@ -2,8 +2,8 @@ module Rails
   module VERSION
     MAJOR = 4
     MINOR = 0
-    TINY  = 0
-    PRE   = nil
+    TINY  = 1
+    PRE   = "rc1"
 
     STRING = [MAJOR, MINOR, TINY, PRE].compact.join(".")
   end