diff --git a/etc/tempest.conf.sample b/etc/tempest.conf.sample
index 4a43282..9de7492 100644
--- a/etc/tempest.conf.sample
+++ b/etc/tempest.conf.sample
@@ -801,7 +801,8 @@
 
 # A list of enabled network extensions with a special entry all which
 # indicates every extension is enabled. Empty list indicates all
-# extensions are disabled (list value)
+# extensions are disabled. To get the list of extensions run: 'neutron
+# ext-list' (list value)
 #api_extensions = all
 
 # Allow the execution of IPv6 subnet tests that use the extended IPv6
diff --git a/tempest/config.py b/tempest/config.py
index fc55723..5628ec9 100644
--- a/tempest/config.py
+++ b/tempest/config.py
@@ -520,9 +520,10 @@
                 help="Allow the execution of IPv6 tests"),
     cfg.ListOpt('api_extensions',
                 default=['all'],
-                help='A list of enabled network extensions with a special '
-                     'entry all which indicates every extension is enabled. '
-                     'Empty list indicates all extensions are disabled'),
+                help="A list of enabled network extensions with a special "
+                     "entry all which indicates every extension is enabled. "
+                     "Empty list indicates all extensions are disabled. "
+                     "To get the list of extensions run: 'neutron ext-list'"),
     cfg.BoolOpt('ipv6_subnet_attributes',
                 default=False,
                 help="Allow the execution of IPv6 subnet tests that use "