diff --git a/django_q/brokers/ironmq.py b/django_q/brokers/ironmq.py
index fd47667..08bb860 100644
--- a/django_q/brokers/ironmq.py
+++ b/django_q/brokers/ironmq.py
@@ -1,3 +1,4 @@
+from requests.exceptions import HTTPError
 from django_q.conf import Conf
 from django_q.brokers import Broker
 from iron_mq import IronMQ
@@ -31,13 +32,19 @@ class IronMQBroker(Broker):
         return self.connection.size()
 
     def delete_queue(self):
-        return self.connection.delete_queue()['msg']
+        try:
+            return self.connection.delete_queue()['msg']
+        except HTTPError:
+            return False
 
     def purge_queue(self):
         return self.connection.clear()
 
     def delete(self, task_id):
-        return self.connection.delete(task_id)['msg']
+        try:
+            return self.connection.delete(task_id)['msg']
+        except HTTPError:
+            return False
 
     def fail(self, task_id):
         self.delete(task_id)
diff --git a/django_q/tests/test_brokers.py b/django_q/tests/test_brokers.py
index 68df44e..9990414 100644
--- a/django_q/tests/test_brokers.py
+++ b/django_q/tests/test_brokers.py
@@ -85,6 +85,13 @@ def test_disque():
         task = broker.dequeue()
         assert task is not None
         broker.acknowledge(task[0])
+    # test duplicate acknowledge
+    # broker.acknowledge(task[0])
+    #
+    # this crashes Disque when followed by a JSCAN
+    # https://github.com/antirez/disque/issues/113
+    # confirmed fix and merge is on the way
+    #
     # delete queue
     broker.enqueue('test')
     broker.enqueue('test')
@@ -139,6 +146,8 @@ def test_ironmq():
         task = broker.dequeue()
         assert task is not None
         broker.acknowledge(task[0])
+    # duplicate acknowledge
+    broker.acknowledge(task[0])
     # delete queue
     broker.enqueue('test')
     broker.enqueue('test')
@@ -195,6 +204,8 @@ def test_sqs():
         task = broker.dequeue()
         assert task is not None
         broker.acknowledge(task[0])
+    # duplicate acknowledge
+    broker.acknowledge(task[0])
     # delete queue
     broker.enqueue('test')
     broker.purge_queue()