diff --git a/HISTORY.rst b/HISTORY.rst
index 6b8bd67e52..e3607d6360 100644
--- a/HISTORY.rst
+++ b/HISTORY.rst
@@ -92,6 +92,11 @@
   address. Closes GitLab issue #522.
 - Add support for subfolder scanning to watchfolders. Closes
   GitLab issue #498.
+- Increased the default value of the index mirroring cache timeout
+  from 10 seconds to 5 minutes. Since version 3.1.5, mirror
+  cache invalidation is tied to index updates. This makes the
+  timeout less relevant. The purpose of the cache timeout is
+  now avoid runaway memory usage.
 
 3.1.9 (2018-11-01)
 ==================
diff --git a/mayan/apps/mirroring/settings.py b/mayan/apps/mirroring/settings.py
index 38cdad4b1d..a1a8128302 100644
--- a/mayan/apps/mirroring/settings.py
+++ b/mayan/apps/mirroring/settings.py
@@ -7,10 +7,10 @@ from smart_settings import Namespace
 namespace = Namespace(name='mirroring', label=_('Mirroring'))
 
 setting_document_lookup_cache_timeout = namespace.add_setting(
-    global_name='MIRRORING_DOCUMENT_CACHE_LOOKUP_TIMEOUT', default=10,
+    global_name='MIRRORING_DOCUMENT_CACHE_LOOKUP_TIMEOUT', default=300,
     help_text=_('Time in seconds to cache the path lookup to a document.'),
 )
 setting_node_lookup_cache_timeout = namespace.add_setting(
-    global_name='MIRRORING_NODE_CACHE_LOOKUP_TIMEOUT', default=10,
+    global_name='MIRRORING_NODE_CACHE_LOOKUP_TIMEOUT', default=300,
     help_text=_('Time in seconds to cache the path lookup to an index node.'),
 )