diff --git a/bin/compose_format b/bin/compose_format
index 093638e..84e4416 100755
--- a/bin/compose_format
+++ b/bin/compose_format
@@ -14,6 +14,9 @@ if __name__ == '__main__':
     parser.add_argument(
         '--ignore_changes', action='store_const', const=False,
         help='ignore changes for return code', default=True)
+    parser.add_argument(
+        '--non_strict', action='store_const', const=True,
+        help='if this is provided, unknown keys errors are ignored', default=False)
     parser.add_argument('files', nargs=argparse.REMAINDER)
     args = parser.parse_args()
     formatter = ComposeFormat()
@@ -22,14 +25,14 @@ if __name__ == '__main__':
         assert args.replace is False, 'replace makes no sense when reading from stdin'
 
         data = sys.stdin.read()
-        formatted = formatter.format_string(data)
+        formatted = formatter.format_string(data, strict=not args.non_strict)
         print(formatted)
         if not args.ignore_changes:
             if data != formatted:
                 sys.exit(1)
 
     for path in args.files:
-        if not formatter.format(path, args.replace):
+        if not formatter.format(path, replace=args.replace, strict=not args.non_strict):
             if args.replace:
                 print('path {} has been changed'.format(path))
             if not args.ignore_changes:
diff --git a/compose_format/__init__.py b/compose_format/__init__.py
index 4f2451a..59ef5f2 100755
--- a/compose_format/__init__.py
+++ b/compose_format/__init__.py
@@ -7,10 +7,24 @@
 class ComposeFormat:
     TOPLEVEL_ORDER = ['version', 'services', 'volumes', 'networks']
     SERVICE_ORDER = [
-        'image', 'command', 'links',
-        'volumes_from', 'volumes', 'expose', 'ports',
-        'extra_hosts', 'restart', 'ulimits', 'tty']
-    BUILD_ORDER = ['context', 'dockerfile']
+        'image', 'command', 'entrypoint', 'container_name',
+        'links', 'volumes_from', 'volumes', 'volume_driver',
+        'build',
+        'expose', 'ports',
+        'net', 'network_mode', 'networks',
+        'labels',
+        'devices',
+        'read_only',
+        'env_file', 'environment',
+        'cpu_shares', 'cpu_quota', 'cpuset', 'domainname', 'hostname', 'ipc',
+        'mac_address', 'mem_limit', 'memswap_limit', 'privileged',
+        'depends_on', 'extends', 'external_links',
+        'stdin_open', 'user', 'working_dir',
+        'extra_hosts', 'restart', 'ulimits', 'tty', 'dns', 'dns_search', 'pid',
+        'security_opt', 'cap_add', 'cap_drop', 'cgroup_parent', 'logging', 'log_driver', 'log_opt',
+        'stopsignal',
+    ]
+    BUILD_ORDER = ['context', 'dockerfile', 'args']
 
     ORDERS = {
         'version': TOPLEVEL_ORDER,
@@ -21,11 +35,11 @@ class ComposeFormat:
     def __init__(self):
         pass
 
-    def format(self, path, replace=False):
+    def format(self, path, replace=False, strict=True):
         with open(path, 'r') as file:
             data = file.read()
         original = data
-        formatted = self.format_string(data, replace=replace)
+        formatted = self.format_string(data, replace=replace, strict=strict)
 
         if replace:
             with open(path, 'w') as file:
@@ -34,8 +48,8 @@ def format(self, path, replace=False):
             print(formatted)
         return original == formatted
 
-    def format_string(self, data, replace=False):
-        data = self.reorder(load(data))
+    def format_string(self, data, replace=False, strict=True):
+        data = self.reorder(load(data), strict=strict)
 
         def is_legacy_version(data):
             if 'version' not in data:
@@ -48,7 +62,7 @@ def is_legacy_version(data):
         return formatted.strip() + '\n'
 
     @staticmethod
-    def reorder(data):
+    def reorder(data, strict=True):
         if type(data) is dict or type(data) is OrderedDict:
             for key in ComposeFormat.ORDERS.keys():
                 if key not in data.keys():
@@ -57,19 +71,26 @@ def reorder(data):
 
                 def order(item):
                     key, _ = item
-                    assert key in current_order, 'key: {0} not known'.format(key)
+                    if strict:
+                        assert key in current_order, 'key: {0} not known'.format(key)
 
                     if key in current_order:
                         return current_order.index(key)
-                    return len(current_order)
+                    return len(current_order) + ComposeFormat.name_to_order(key)
 
-                result = {key: ComposeFormat.reorder(value) for key, value in data.items()}
+                result = {key: ComposeFormat.reorder(value, strict=strict) for key, value in data.items()}
                 result = OrderedDict(sorted(result.items(), key=order))
 
                 return result
-            return {key: ComposeFormat.reorder(value) for key, value in data.items()}
+            return {key: ComposeFormat.reorder(value, strict=strict) for key, value in data.items()}
         if type(data) is list:
-            return sorted([ComposeFormat.reorder(item) for item in data])
+            return sorted([ComposeFormat.reorder(item, strict=strict) for item in data])
         if len(str(data)) >= 1 and str(data)[0].isdigit():
             return '\'{}\''.format(data)
         return data
+
+    @staticmethod
+    def name_to_order(value):
+        from functools import reduce
+
+        return reduce(lambda left, right: (left * 256 + right), (ord(char) for char in value))
diff --git a/features/format.feature b/features/format.feature
index 6cc80b9..244d123 100644
--- a/features/format.feature
+++ b/features/format.feature
@@ -169,3 +169,22 @@ Feature: Format
           ports:
             - '10000'
       """
+
+  Scenario: Alphabetic Order for unknown keys (--non_strict)
+    Given a file named "compose.yml" with:
+      """
+      foo:
+        image: bar
+        aaa: unknown
+        ccc: unknown
+        bbb: unknown
+      """
+    When I run `bin/compose_format --non_strict compose.yml`
+    Then it should pass with exactly:
+      """
+      foo:
+        image: bar
+        aaa: unknown
+        bbb: unknown
+        ccc: unknown
+      """
diff --git a/setup.py b/setup.py
index 96bfed1..cf2c5d3 100644
--- a/setup.py
+++ b/setup.py
@@ -7,7 +7,7 @@ def readme():
 
 setup(
     name='compose_format',
-    version='0.1.4',
+    version='0.1.5',
     description='format docker-compose files',
     long_description=readme(),
     url='http://github.com/funkwerk/compose_format',