diff --git a/resque-lonely_job.gemspec b/resque-lonely_job.gemspec
index 933237a..9d78dae 100644
--- a/resque-lonely_job.gemspec
+++ b/resque-lonely_job.gemspec
@@ -19,6 +19,7 @@ Gem::Specification.new do |gem|
   gem.add_development_dependency 'rake'
   gem.add_development_dependency 'rspec'
   gem.add_development_dependency 'debugger'
+  gem.add_development_dependency 'timecop'
 
   gem.description   = <<desc
 Ensures that for a given queue, only one worker is working on a job at any given time.
diff --git a/spec/lib/lonely_job_spec.rb b/spec/lib/lonely_job_spec.rb
index 675b1fe..c6cca4f 100644
--- a/spec/lib/lonely_job_spec.rb
+++ b/spec/lib/lonely_job_spec.rb
@@ -32,6 +32,37 @@ def self.perform(account_id, *args); end
       SerialJob.can_lock_queue?(:serial_work).should be_true
       SerialJob.can_lock_queue?(:serial_work).should be_false
     end
+
+    it 'cannot lock a queue with active lock' do
+      SerialJob.can_lock_queue?(:serial_work).should be_true
+      Timecop.travel(Date.today + 1) do
+        SerialJob.can_lock_queue?(:serial_work).should be_false
+      end
+    end
+
+    it 'can relock a queue with expired lock' do
+      SerialJob.can_lock_queue?(:serial_work).should be_true
+
+      Timecop.travel(Date.today + 10) do
+        SerialJob.can_lock_queue?(:serial_work).should be_true
+      end
+    end
+
+    it 'solves race condition with getset' do
+      SerialJob.can_lock_queue?(:serial_work).should be_true
+
+      Timecop.travel(Date.today + 10) do
+        threads = (1..10).to_a.map {
+          Thread.new {
+            Thread.current[:locked] = SerialJob.can_lock_queue?(:serial_work)
+          }
+        }
+
+        # Only one worker should acquire lock
+        locks = threads.map {|t| t.join; t[:locked] }
+        locks.count(true).should == 1
+      end
+    end
   end
 
   describe ".perform" do
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index f7b36fc..9c424f7 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -5,6 +5,7 @@
 require 'mock_redis'
 require 'resque'
 require 'resque-lonely_job'
+require 'timecop'
 
 RSpec.configure do |config|
   config.before(:suite) do