diff --git a/django/db/models/fields/files.py b/django/db/models/fields/files.py
index 6f1f183d4f..34cf84dbc0 100644
--- a/django/db/models/fields/files.py
+++ b/django/db/models/fields/files.py
@@ -3,6 +3,7 @@ import os
 
 from django import forms
 from django.db.models.fields import Field
+from django.core.exceptions import ValidationError
 from django.core.files.base import File
 from django.core.files.storage import default_storage
 from django.core.files.images import ImageFile
@@ -204,6 +205,11 @@ class FileDescriptor(object):
         instance.__dict__[self.field.name] = value
 
 class FileField(Field):
+
+    default_error_messages = {
+        'max_length': _(u'Filename is %(extra)d characters too long.')
+    }
+
     # The class to wrap instance attributes in. Accessing the file object off
     # the instance will always return an instance of attr_class.
     attr_class = FieldFile
@@ -226,6 +232,21 @@ class FileField(Field):
         kwargs['max_length'] = kwargs.get('max_length', 100)
         super(FileField, self).__init__(verbose_name, name, **kwargs)
 
+    def validate(self, value, model_instance):
+        """
+        Validates that the generated file name still fits within max_length.
+        """
+        # The generated file name stored in the database is generally longer
+        # than the uploaded file name. Using the length of generated name in
+        # the error message would be confusing. However, in the common case
+        # (ie. upload_to='path/to/upload/dir'), the length of the generated
+        # name equals the length of the uploaded name plus a constant. Thus
+        # we can tell the user how much shorter the name should be (roughly).
+        length = len(self.generate_filename(model_instance, value.name))
+        if self.max_length and length > self.max_length:
+            error_values = {'extra': length - self.max_length}
+            raise ValidationError(self.error_messages['max_length'] % error_values)
+
     def get_internal_type(self):
         return "FileField"
 
diff --git a/tests/regressiontests/model_fields/tests.py b/tests/regressiontests/model_fields/tests.py
index ea1e1c7d99..4b48616e99 100644
--- a/tests/regressiontests/model_fields/tests.py
+++ b/tests/regressiontests/model_fields/tests.py
@@ -365,3 +365,15 @@ class FileFieldTests(unittest.TestCase):
         field = d._meta.get_field('myfile')
         field.save_form_data(d, 'else.txt')
         self.assertEqual(d.myfile, 'else.txt')
+
+    def test_max_length(self):
+        """
+        Test that FileField validates the length of the generated file name
+        that will be stored in the database. Regression for #9893.
+
+        """
+        # upload_to = 'unused', so file names are saved as 'unused/xxxxx'.
+        # max_length = 100, so names longer than 93 characters are rejected.
+        Document(myfile=93 * 'x').full_clean()
+        with self.assertRaises(ValidationError):
+            Document(myfile=94 * 'x').full_clean()