diff --git a/rq/worker.py b/rq/worker.py
index 4410ce6..a05a6ba 100644
--- a/rq/worker.py
+++ b/rq/worker.py
@@ -694,18 +694,20 @@ class Worker(object):
         signal.signal(signal.SIGINT, signal.SIG_IGN)
         signal.signal(signal.SIGTERM, signal.SIG_DFL)
 
-    def prepare_job_execution(self, job):
+    def prepare_job_execution(self, job, heartbeat_ttl=None):
         """Performs misc bookkeeping like updating states prior to
         job execution.
         """
         timeout = (job.timeout or 180) + 60
 
+        if heartbeat_ttl is None:
+            heartbeat_ttl = self.job_monitoring_interval + 5
+
         with self.connection._pipeline() as pipeline:
             self.set_state(WorkerStatus.BUSY, pipeline=pipeline)
             self.set_current_job_id(job.id, pipeline=pipeline)
-            self.heartbeat(self.job_monitoring_interval + 5, pipeline=pipeline)
-            registry = StartedJobRegistry(job.origin,
-                                          self.connection,
+            self.heartbeat(heartbeat_ttl, pipeline=pipeline)
+            registry = StartedJobRegistry(job.origin, self.connection,
                                           job_class=self.job_class)
             registry.add(job, timeout, pipeline=pipeline)
             job.set_status(JobStatus.STARTED, pipeline=pipeline)
@@ -778,11 +780,11 @@ class Worker(object):
                 except WatchError:
                     continue
 
-    def perform_job(self, job, queue):
+    def perform_job(self, job, queue, heartbeat_ttl=None):
         """Performs the actual work of a job.  Will/should only be called
         inside the work horse's process.
         """
-        self.prepare_job_execution(job)
+        self.prepare_job_execution(job, heartbeat_ttl)
 
         push_connection(self.connection)
 
@@ -910,9 +912,10 @@ class SimpleWorker(Worker):
     def main_work_horse(self, *args, **kwargs):
         raise NotImplementedError("Test worker does not implement this method")
 
-    def execute_job(self, *args, **kwargs):
+    def execute_job(self, job, queue):
         """Execute job in same thread/process, do not fork()"""
-        return self.perform_job(*args, **kwargs)
+        timeout = (job.timeout or DEFAULT_WORKER_TTL) + 5
+        return self.perform_job(job, queue, heartbeat_ttl=timeout)
 
 
 class HerokuWorker(Worker):
diff --git a/tests/fixtures.py b/tests/fixtures.py
index 4ef904a..b497b6c 100644
--- a/tests/fixtures.py
+++ b/tests/fixtures.py
@@ -119,6 +119,14 @@ def black_hole(job, *exc_info):
     return False
 
 
+def save_key_ttl(key):
+    # Stores key ttl in meta
+    job = get_current_job()
+    ttl = job.connection.ttl(key)
+    job.meta = {'ttl': ttl}
+    job.save_meta()
+
+
 def long_running_job(timeout=10):
     time.sleep(timeout)
     return 'Done sleeping...'
diff --git a/tests/test_worker.py b/tests/test_worker.py
index d9c88b6..868ef8d 100644
--- a/tests/test_worker.py
+++ b/tests/test_worker.py
@@ -21,11 +21,11 @@ import mock
 from mock import Mock
 
 from tests import RQTestCase, slow
-from tests.fixtures import (create_file, create_file_after_timeout,
-                            div_by_zero, do_nothing, say_hello, say_pid,
-                            run_dummy_heroku_worker, access_self,
-                            modify_self, modify_self_and_error,
-                            long_running_job)
+from tests.fixtures import (
+    create_file, create_file_after_timeout, div_by_zero, do_nothing, say_hello,
+    say_pid, run_dummy_heroku_worker, access_self, modify_self,
+    modify_self_and_error, long_running_job, save_key_ttl
+)
 
 from rq import (get_failed_queue, Queue, SimpleWorker, Worker,
                 get_current_connection)
@@ -537,6 +537,17 @@ class TestWorker(RQTestCase):
         self.assertEqual(job.result, os.getpid(),
                          'PID mismatch, fork() is not supposed to happen here')
 
+    def test_simpleworker_heartbeat_ttl(self):
+        """SimpleWorker's key must last longer than job.timeout when working"""
+        queue = Queue('foo')
+
+        worker = SimpleWorker([queue])
+        job_timeout = 300
+        job = queue.enqueue(save_key_ttl, worker.key, timeout=job_timeout)
+        worker.work(burst=True)
+        job.refresh()
+        self.assertGreater(job.meta['ttl'], job_timeout)
+
     def test_prepare_job_execution(self):
         """Prepare job execution does the necessary bookkeeping."""
         queue = Queue(connection=self.testconn)