diff --git a/README.textile b/README.textile
index c02d39a06..61c6dc738 100644
--- a/README.textile
+++ b/README.textile
@@ -40,7 +40,7 @@ After delayed_job is installed, you will need to setup the backend.
 
 h2. Backends
 
-delayed_job supports multiple backends for storing the job queue. There are currently implementations for Active Record, MongoMapper, and DataMapper.
+delayed_job supports multiple backends for storing the job queue. "See the wiki for other backends":http://wiki.github.com/collectiveidea/delayed_job/backends besides Active Record.
 
 h3. Active Record
 
diff --git a/delayed_job.gemspec b/delayed_job.gemspec
index f46e090ab..cc2e05896 100644
--- a/delayed_job.gemspec
+++ b/delayed_job.gemspec
@@ -2,7 +2,7 @@
 
 Gem::Specification.new do |s|
   s.name              = 'delayed_job'
-  s.version           = '2.1.0.pre'
+  s.version           = '2.1.0.pre2'
   s.authors           = ["Brandon Keepers", "Tobias L\303\274tke"]
   s.summary           = 'Database-backed asynchronous priority queue system -- Extracted from Shopify'
   s.description       = "Delayed_job (or DJ) encapsulates the common pattern of asynchronously executing longer tasks in the background. It is a direct extraction from Shopify where the job table is responsible for a multitude of core tasks.
@@ -18,7 +18,7 @@ This gem is collectiveidea's fork (http://github.com/collectiveidea/delayed_job)
   s.test_files        = Dir.glob('spec/**/*')
   
   s.add_runtime_dependency      'daemons'
-  s.add_runtime_dependency      'activesupport' '~>3'
+  s.add_runtime_dependency      'activesupport', '~>3.0'
   s.add_development_dependency  'rspec'
   s.add_development_dependency  'sqlite3-ruby'
   s.add_development_dependency  'activerecord'
diff --git a/lib/delayed/worker.rb b/lib/delayed/worker.rb
index ecc4845a9..bc90b70c4 100644
--- a/lib/delayed/worker.rb
+++ b/lib/delayed/worker.rb
@@ -38,7 +38,7 @@ def self.backend=(backend)
     end
     
     def self.guess_backend
-      self.backend = :active_record if defined?(ActiveRecord)
+      self.backend ||= :active_record if defined?(ActiveRecord)
     end
 
     def initialize(options={})
diff --git a/spec/worker_spec.rb b/spec/worker_spec.rb
index 397e9073f..62bc70edf 100644
--- a/spec/worker_spec.rb
+++ b/spec/worker_spec.rb
@@ -10,10 +10,28 @@
     it "should set the Delayed::Job constant to the backend" do
       Delayed::Job.should == @clazz
     end
-    
+
     it "should set backend with a symbol" do
       Delayed::Worker.backend = :active_record
       Delayed::Worker.backend.should == Delayed::Backend::ActiveRecord::Job
     end
   end
+
+  describe "guess_backend" do
+    after do
+      Delayed::Worker.backend = :active_record
+    end
+
+    it "should set to active_record if nil" do
+      Delayed::Worker.backend = nil
+      lambda {
+        Delayed::Worker.guess_backend
+      }.should change { Delayed::Worker.backend }.to(Delayed::Backend::ActiveRecord::Job)
+    end
+
+    it "should not override the existing backend" do
+      Delayed::Worker.backend = Class.new
+      lambda { Delayed::Worker.guess_backend }.should_not change { Delayed::Worker.backend }
+    end
+  end
 end