diff --git a/tailbone/forms2/core.py b/tailbone/forms2/core.py
index d7ad0e5a..5d7148c2 100644
--- a/tailbone/forms2/core.py
+++ b/tailbone/forms2/core.py
@@ -178,7 +178,7 @@ class Form(object):
 
     def __init__(self, fields=None, schema=None, request=None, readonly=False, readonly_fields=[],
                  model_instance=None, model_class=None, nodes={}, enums={}, labels={}, renderers={},
-                 widgets={}, defaults={}, action_url=None, cancel_url=None):
+                 widgets={}, defaults={}, validators={}, required={}, action_url=None, cancel_url=None):
 
         self.fields = list(fields) if fields is not None else None
         self.schema = schema
@@ -197,6 +197,8 @@ class Form(object):
         self.renderers = renderers or {}
         self.widgets = widgets or {}
         self.defaults = defaults or {}
+        self.validators = validators or {}
+        self.required = required or {}
         self.action_url = action_url
         self.cancel_url = cancel_url
 
@@ -271,6 +273,19 @@ class Form(object):
                 if key in schema:
                     schema[key].default = default
 
+            # apply any validators
+            for key, validator in self.validators.items():
+                if key in schema:
+                    schema[key].validator = validator
+
+            # apply required flags
+            for key, required in self.required.items():
+                if key in schema:
+                    if required:
+                        schema[key].missing = colander.required
+                    else:
+                        schema[key].missing = None # TODO?
+
             self.schema = schema
 
         return self.schema
@@ -325,14 +340,13 @@ class Form(object):
         self.widgets[key] = widget
 
     def set_validator(self, key, validator):
-        schema = self.make_schema()
-        schema[key].validator = validator
+        self.validators[key] = validator
 
-    def set_required(self, key, required):
+    def set_required(self, key, required=True):
         """
         Set whether or not value is required for a given field.
         """
-        raise NotImplementedError # TODO        
+        self.required[key] = required
 
     def set_default(self, key, value):
         """