diff --git a/lib/ansible/constants.py b/lib/ansible/constants.py
index 94070f641f2..6bf87e51f8a 100644
--- a/lib/ansible/constants.py
+++ b/lib/ansible/constants.py
@@ -93,8 +93,8 @@ else:
     DIST_MODULE_PATH = '/usr/share/ansible/'
 
 # check all of these extensions when looking for yaml files for things like
-# group variables
-YAML_FILENAME_EXTENSIONS = [ "", ".yml", ".yaml" ]
+# group variables -- really anything we can load
+YAML_FILENAME_EXTENSIONS = [ "", ".yml", ".yaml", ".json" ]
 
 # sections in config file
 DEFAULTS='defaults'
diff --git a/lib/ansible/playbook/play.py b/lib/ansible/playbook/play.py
index aaa79358825..41f246cbbb3 100644
--- a/lib/ansible/playbook/play.py
+++ b/lib/ansible/playbook/play.py
@@ -448,6 +448,7 @@ class Play(object):
                  os.path.join(basepath, 'main'),
                  os.path.join(basepath, 'main.yml'),
                  os.path.join(basepath, 'main.yaml'),
+                 os.path.join(basepath, 'main.json'),
                 )
         if sum([os.path.isfile(x) for x in mains]) > 1:
             raise errors.AnsibleError("found multiple main files at %s, only one allowed" % (basepath))