diff --git a/gluon/contrib/pydal b/gluon/contrib/pydal
index 97a45307..83d97c64 160000
--- a/gluon/contrib/pydal
+++ b/gluon/contrib/pydal
@@ -1 +1 @@
-Subproject commit 97a45307a30ef7ca4fef4c8d3a4308d2874a3e4d
+Subproject commit 83d97c6466ed563991ac4d0d2358a0aaf12c7f68
diff --git a/gluon/dal.py b/gluon/dal.py
index 19896993..3c7c1cdf 100644
--- a/gluon/dal.py
+++ b/gluon/dal.py
@@ -5,14 +5,120 @@ from pydal import Field, SQLCustomType, geoPoint, geoLine, geoPolygon
 
 
 from gluon import serializers as w2p_serializers
-from gluon import validators as w2p_validators
 from gluon.utils import web2py_uuid
 from gluon import sqlhtml
 
 
+def _default_validators(field):
+    """
+    Field type validation, using web2py's validators mechanism.
+
+    makes sure the content of a field is in line with the declared
+    fieldtype
+    """
+    from gluon import validators
+    db = field.db
+    field_type, field_length = field.type, field.length
+    requires = []
+
+    def ff(r, id):
+        row = r(id)
+        if not row:
+            return str(id)
+        elif hasattr(r, '_format') and isinstance(r._format, str):
+            return r._format % row
+        elif hasattr(r, '_format') and callable(r._format):
+            return r._format(row)
+        else:
+            return str(id)
+
+    if field_type in (('string', 'text', 'password')):
+        requires.append(validators.IS_LENGTH(field_length))
+    elif field_type == 'json':
+        requires.append(validators.IS_EMPTY_OR(validators.IS_JSON()))
+    elif field_type == 'double' or field_type == 'float':
+        requires.append(validators.IS_FLOAT_IN_RANGE(-1e100, 1e100))
+    elif field_type == 'integer':
+        requires.append(validators.IS_INT_IN_RANGE(-2**31, 2**31))
+    elif field_type == 'bigint':
+        requires.append(validators.IS_INT_IN_RANGE(-2**63, 2**63))
+    elif field_type.startswith('decimal'):
+        requires.append(validators.IS_DECIMAL_IN_RANGE(-10**10, 10**10))
+    elif field_type == 'date':
+        requires.append(validators.IS_DATE())
+    elif field_type == 'time':
+        requires.append(validators.IS_TIME())
+    elif field_type == 'datetime':
+        requires.append(validators.IS_DATETIME())
+    elif db and field_type.startswith('reference') and \
+            field_type.find('.') < 0 and \
+            field_type[10:] in db.tables:
+        referenced = db[field_type[10:]]
+
+        def repr_ref(id, row=None, r=referenced, f=ff):
+            return f(r, id)
+
+        field.represent = field.represent or repr_ref
+        if hasattr(referenced, '_format') and referenced._format:
+            requires = validators.IS_IN_DB(db, referenced._id,
+                                           referenced._format)
+            if field.unique:
+                requires._and = validators.IS_NOT_IN_DB(db, field)
+            if field.tablename == field_type[10:]:
+                return validators.IS_EMPTY_OR(requires)
+            return requires
+    elif db and field_type.startswith('list:reference') and \
+            field_type.find('.') < 0 and \
+            field_type[15:] in db.tables:
+        referenced = db[field_type[15:]]
+
+        def list_ref_repr(ids, row=None, r=referenced, f=ff):
+            if not ids:
+                return None
+            from ..adapters.google import GoogleDatastoreAdapter
+            refs = None
+            db, id = r._db, r._id
+            if isinstance(db._adapter, GoogleDatastoreAdapter):
+                def count(values):
+                    return db(id.belongs(values)).select(id)
+                rx = range(0, len(ids), 30)
+                refs = reduce(lambda a, b: a & b, [count(ids[i:i+30])
+                              for i in rx])
+            else:
+                refs = db(id.belongs(ids)).select(id)
+            return (refs and ', '.join(f(r, x.id) for x in refs) or '')
+
+        field.represent = field.represent or list_ref_repr
+        if hasattr(referenced, '_format') and referenced._format:
+            requires = validators.IS_IN_DB(db, referenced._id,
+                                           referenced._format, multiple=True)
+        else:
+            requires = validators.IS_IN_DB(db, referenced._id,
+                                           multiple=True)
+        if field.unique:
+            requires._and = validators.IS_NOT_IN_DB(db, field)
+        if not field.notnull:
+            requires = validators.IS_EMPTY_OR(requires)
+        return requires
+    elif field_type.startswith('list:'):
+        def repr_list(values, row=None):
+            return', '.join(str(v) for v in (values or []))
+
+        field.represent = field.represent or repr_list
+
+    if field.unique:
+        requires.append(validators.IS_NOT_IN_DB(db, field))
+    sff = ['in', 'do', 'da', 'ti', 'de', 'bo']
+    if field.notnull and not field_type[:2] in sff:
+        requires.append(validators.IS_NOT_EMPTY())
+    elif not field.notnull and field_type[:2] in sff and requires:
+        requires[0] = validators.IS_EMPTY_OR(requires[0])
+    return requires
+
+
 class DAL(pyDAL):
     serializers = w2p_serializers
-    validators = w2p_validators
+    validators_method = _default_validators
     uuid = web2py_uuid
     representers = {
         'rows_render': sqlhtml.represent,