diff --git a/tiramisu_cmdline_parser.py b/tiramisu_cmdline_parser.py
index a6cec66..c2dbe17 100644
--- a/tiramisu_cmdline_parser.py
+++ b/tiramisu_cmdline_parser.py
@@ -136,6 +136,11 @@ class TiramisuCmdlineParser(ArgumentParser):
     def add_subparsers(self, *args, **kwargs):
         raise NotImplementedError('do not use add_subparsers')
 
+    def _gen_argument(self, name, properties):
+        if len(name) == 1 and 'longargument' not in properties:
+            return self.prefix_chars + name
+        return self.prefix_chars * 2 + name
+
     def _config_to_argparser(self,
                              _forhelp: bool,
                              config,
@@ -173,10 +178,7 @@ class TiramisuCmdlineParser(ArgumentParser):
             else:
                 if self.fullpath and prefix:
                     name = prefix + '.' + name
-                if len(name) == 1 and 'longargument' not in properties:
-                    args = [self.prefix_chars + name]
-                else:
-                    args = [self.prefix_chars * 2 + name]
+                args = [self._gen_argument(name, properties)]
                 if _forhelp and 'mandatory' in properties:
                     kwargs['required'] = True
             if option.type() == 'bool':
@@ -234,6 +236,13 @@ class TiramisuCmdlineParser(ArgumentParser):
                 self.error('the following arguments are required: {}'.format(name))
             else:
                 self.error('unrecognized arguments: {}'.format(name))
+        for key in self.config.value.mandatory():
+            if self.fullpath or '.' not in key:
+                name = key
+            else:
+                name = key.rsplit('.', 1)[1]
+            args = self._gen_argument(name, self.config.option(key).property.get())
+            self.error('the following arguments are required: {}'.format(args))
         return namespaces
 
     def format_usage(self,