diff --git a/src/Orchard.Tests/DataMigration/SchemaBuilderTests.cs b/src/Orchard.Tests/DataMigration/SchemaBuilderTests.cs
index bf93a8d80..59f493f52 100644
--- a/src/Orchard.Tests/DataMigration/SchemaBuilderTests.cs
+++ b/src/Orchard.Tests/DataMigration/SchemaBuilderTests.cs
@@ -1,4 +1,5 @@
-using System.Data;
+using System;
+using System.Data;
 using System.Linq;
 using Autofac;
 using NHibernate;
@@ -37,8 +38,6 @@ namespace Orchard.Tests.DataMigration {
 
             var builder = new ContainerBuilder();
 
-            builder.RegisterInstance(new ShellSettings { DataTablePrefix = "TEST_", DataProvider = "SqlCe" });
-
             var session = _sessionFactory.OpenSession();
             builder.RegisterInstance(appDataFolder).As<IAppDataFolder>();
             builder.RegisterType<SqlCeDataServicesProvider>().As<IDataServicesProvider>();
@@ -49,7 +48,7 @@ namespace Orchard.Tests.DataMigration {
             builder.RegisterType<SessionFactoryHolder>().As<ISessionFactoryHolder>();
             builder.RegisterInstance(new DefaultContentManagerTests.TestSessionLocator(session)).As<ISessionLocator>();
             builder.RegisterInstance(new ShellBlueprint { Records = Enumerable.Empty<RecordBlueprint>() }).As<ShellBlueprint>();
-            builder.RegisterInstance(new ShellSettings { Name = "temp", DataProvider = "SqlCe", DataTablePrefix = "TEST_" }).As<ShellSettings>();
+            builder.RegisterInstance(new ShellSettings { Name = "temp", DataProvider = "SqlCe", DataTablePrefix = "TEST" }).As<ShellSettings>();
             builder.RegisterModule(new DataModule());
             _container = builder.Build();
 
@@ -154,6 +153,61 @@ namespace Orchard.Tests.DataMigration {
                     .Column("UserId", DbType.Int32, column => column.NotNull()))
                 .CreateForeignKey("FK_User", "Address", new[] { "UserId" }, "User", new[] { "Id" })
                 .DropForeignKey("Address", "FK_User");
+        }
+
+        [Test, ExpectedException]
+        public void BiggerDataShouldNotFit() {
+            _schemaBuilder
+                .CreateTable("ContentItemRecord", table => table
+                    .Column("Id", DbType.Int32, column => column.PrimaryKey().Identity())
+                    .Column("Data", DbType.String, column => column.WithLength(255)));
+
+            // should write successfully less than 255 chars
+            _schemaBuilder
+                .ExecuteSql("insert into TEST_ContentItemRecord (Data) values('Hello World')");
+
+            // should throw an exception if trying to write more data
+            _schemaBuilder
+                .ExecuteSql(String.Format("insert into TEST_ContentItemRecord (Data) values('{0}')", new String('x', 256)));
+
+            _schemaBuilder
+                .AlterTable("ContentItemRecord", table => table
+                    .AlterColumn("Data", column => column.WithType(DbType.String).WithLength(257)));
+
+            _schemaBuilder
+                .ExecuteSql(String.Format("insert into TEST_ContentItemRecord (Data) values('{0}')", new String('x', 256)));
+        }
+
+        [Test]
+        public void ShouldAllowFieldSizeAlteration() {
+            _schemaBuilder
+                .CreateTable("ContentItemRecord", table => table
+                    .Column("Id", DbType.Int32, column => column.PrimaryKey().Identity())
+                    .Column("Data", DbType.String, column => column.WithLength(255)));
+
+            // should write successfully less than 255 chars
+            _schemaBuilder
+                .ExecuteSql("insert into TEST_ContentItemRecord (Data) values('Hello World')");
+
+            _schemaBuilder
+                .AlterTable("ContentItemRecord", table => table
+                    .AlterColumn("Data", column => column.WithType(DbType.String).WithLength(2048)));
+
+            // should write successfully a bigger value now
+            _schemaBuilder
+                .ExecuteSql(String.Format("insert into TEST_ContentItemRecord (Data) values('{0}')", new String('x', 2048)));
+        }
+
+        [Test, ExpectedException(typeof(OrchardException))]
+        public void ChangingSizeWithoutTypeShouldNotBeAllowed() {
+            _schemaBuilder
+                .CreateTable("ContentItemRecord", table => table
+                    .Column("Id", DbType.Int32, column => column.PrimaryKey().Identity())
+                    .Column("Data", DbType.String, column => column.WithLength(255)));
+
+            _schemaBuilder
+                .AlterTable("ContentItemRecord", table => table
+                    .AlterColumn("Data", column => column.WithLength(2048)));
 
         }
     }
diff --git a/src/Orchard/ContentManagement/DataMigrations/FrameworkDataMigration.cs b/src/Orchard/ContentManagement/DataMigrations/FrameworkDataMigration.cs
index b1dcca7ed..5cdaaf79f 100644
--- a/src/Orchard/ContentManagement/DataMigrations/FrameworkDataMigration.cs
+++ b/src/Orchard/ContentManagement/DataMigrations/FrameworkDataMigration.cs
@@ -1,4 +1,5 @@
-using Orchard.Data.Migration;
+using System.Data;
+using Orchard.Data.Migration;
 
 namespace Orchard.ContentManagement.DataMigrations {
     public class FrameworkDataMigration : DataMigrationImpl {
@@ -35,5 +36,13 @@ namespace Orchard.ContentManagement.DataMigrations {
 
             return 1;
         }
+
+        public int UpdateFrom1() {
+            SchemaBuilder
+                .AlterTable("ContentItemRecord", table => table
+                    .AlterColumn("Data", column => column.WithType(DbType.String).Unlimited()));
+
+            return 2;
+        }
     }
 }
\ No newline at end of file
diff --git a/src/Orchard/Data/Migration/Interpreters/DefaultDataMigrationInterpreter.cs b/src/Orchard/Data/Migration/Interpreters/DefaultDataMigrationInterpreter.cs
index 86b7390a8..6377aa25f 100644
--- a/src/Orchard/Data/Migration/Interpreters/DefaultDataMigrationInterpreter.cs
+++ b/src/Orchard/Data/Migration/Interpreters/DefaultDataMigrationInterpreter.cs
@@ -39,7 +39,7 @@ namespace Orchard.Data.Migration.Interpreters {
             _reportsCoordinator = reportsCoordinator;
 
             Logger = NullLogger.Instance;
-
+            T = NullLocalizer.Instance;
             var configuration = _sessionFactoryHolder.GetConfiguration();
             _dialect = Dialect.GetDialect(configuration.Properties);
         }
@@ -192,6 +192,11 @@ namespace Orchard.Data.Migration.Interpreters {
             if (command.DbType != DbType.Object) {
                 builder.Append(GetTypeName(command.DbType, command.Length, command.Precision, command.Scale));
             }
+            else {
+                if(command.Length > 0 || command.Precision > 0 || command.Scale > 0) {
+                    throw new OrchardException(T("Error while executing data migration: you need to specify the field's type in order to change it's properies"));
+                }
+            }
 
             // [default value]
             if (!string.IsNullOrEmpty(command.Default)) {