diff --git a/README.markdown b/README.markdown
index 6dce964..0a4adc9 100644
--- a/README.markdown
+++ b/README.markdown
@@ -525,6 +525,13 @@ DatabaseCleaner.allow_production = true
 DatabaseCleaner.allow_remote_database_url = true
 ```
 
+In Ruby, a URL whitelist can be specified. When specified, DatabaseCleaner will only allow `DATABASE_URL` to be equal
+to one of the values specified in the url whitelist like so:
+
+```ruby
+DatabaseCleaner.url_whitelist = ['postgres://postgres@localhost', 'postgres://foo@bar']
+```
+
 ## Debugging
 
 In rare cases DatabaseCleaner will encounter errors that it will log.  By default it uses STDOUT set to the ERROR level but you can configure this to use whatever Logger you desire.
diff --git a/lib/database_cleaner.rb b/lib/database_cleaner.rb
index 1174bda..07843e9 100644
--- a/lib/database_cleaner.rb
+++ b/lib/database_cleaner.rb
@@ -3,7 +3,7 @@ require 'database_cleaner/configuration'
 
 module DatabaseCleaner
   class << self
-    attr_accessor :allow_remote_database_url, :allow_production
+    attr_accessor :allow_remote_database_url, :allow_production, :url_whitelist
 
     def can_detect_orm?
       DatabaseCleaner::Base.autodetect_orm
diff --git a/lib/database_cleaner/safeguard.rb b/lib/database_cleaner/safeguard.rb
index b885391..51205d9 100644
--- a/lib/database_cleaner/safeguard.rb
+++ b/lib/database_cleaner/safeguard.rb
@@ -12,8 +12,35 @@ module DatabaseCleaner
           super("ENV['#{env}'] is set to production. Please refer to https://github.com/DatabaseCleaner/database_cleaner#safeguards")
         end
       end
+
+      class NotWhitelistedUrl < Error
+        def initialize
+          super("ENV['DATABASE_URL'] is set to a URL that is not on the whitelist. Please refer to https://github.com/DatabaseCleaner/database_cleaner#safeguards")
+        end
+      end
     end
 
+    class WhitelistedUrl
+      def run
+        raise Error::NotWhitelistedUrl if !skip? && given?
+      end
+
+      private
+
+        def given?
+          !whitelisted?(ENV['DATABASE_URL'])
+        end
+
+        def whitelisted?(url)
+          DatabaseCleaner.url_whitelist.include?(url)
+        end
+
+        def skip?
+          !DatabaseCleaner.url_whitelist
+        end
+    end
+
+
     class RemoteDatabaseUrl
       LOCAL = %w(localhost 127.0.0.1)
 
@@ -33,7 +60,8 @@ module DatabaseCleaner
 
         def skip?
           ENV['DATABASE_CLEANER_ALLOW_REMOTE_DATABASE_URL'] ||
-            DatabaseCleaner.allow_remote_database_url
+            DatabaseCleaner.allow_remote_database_url ||
+            DatabaseCleaner.url_whitelist
         end
     end
 
@@ -62,7 +90,8 @@ module DatabaseCleaner
 
     CHECKS = [
       RemoteDatabaseUrl,
-      Production
+      Production,
+      WhitelistedUrl
     ]
 
     def run