diff --git a/EF6.PG.Tests/EntityFrameworkMigrationTests.cs b/EF6.PG.Tests/EntityFrameworkMigrationTests.cs
index 3fde9fb..224bafe 100644
--- a/EF6.PG.Tests/EntityFrameworkMigrationTests.cs
+++ b/EF6.PG.Tests/EntityFrameworkMigrationTests.cs
@@ -217,6 +217,20 @@ public void DatabaseExistsCreateDelete()
 
         [Test]
         public void AddColumnOperation()
+        {
+            var operations = new List<MigrationOperation>();
+            operations.Add(new AddColumnOperation("tableName", new ColumnModel(PrimitiveTypeKind.Double)
+            {
+                Name = "columnName",
+                IsNullable = false
+            }));
+            var statments = new NpgsqlMigrationSqlGenerator().Generate(operations, _backendVersion.ToString());
+            Assert.AreEqual(1, statments.Count());
+            Assert.AreEqual("ALTER TABLE \"tableName\" ADD \"columnName\" float8 NOT NULL DEFAULT 0", statments.ElementAt(0).Sql);
+        }
+
+        [Test]
+        public void AddColumnOperationNullable()
         {
             var operations = new List<MigrationOperation>();
             operations.Add(new AddColumnOperation("tableName", new ColumnModel(PrimitiveTypeKind.Double)
@@ -262,7 +276,23 @@ public void AlterColumnOperation()
             var operations = new List<MigrationOperation>();
             operations.Add(new AlterColumnOperation("tableName", new ColumnModel(PrimitiveTypeKind.Double)
             {
-                Name = "columnName"
+                Name = "columnName",
+                IsNullable = false
+            }, false));
+            var statments = new NpgsqlMigrationSqlGenerator().Generate(operations, _backendVersion.ToString());
+            Assert.AreEqual(3, statments.Count());
+            Assert.AreEqual("ALTER TABLE \"tableName\" ALTER COLUMN \"columnName\" TYPE float8", statments.ElementAt(0).Sql);
+            Assert.AreEqual("ALTER TABLE \"tableName\" ALTER COLUMN \"columnName\" SET NOT NULL", statments.ElementAt(1).Sql);
+            Assert.AreEqual("ALTER TABLE \"tableName\" ALTER COLUMN \"columnName\" SET DEFAULT 0", statments.ElementAt(2).Sql);
+        }
+
+        [Test]
+        public void AlterColumnOperationNullable()
+        {
+            var operations = new List<MigrationOperation>();
+            operations.Add(new AlterColumnOperation("tableName", new ColumnModel(PrimitiveTypeKind.Double)
+            {
+                Name = "columnName",
             }, false));
             var statments = new NpgsqlMigrationSqlGenerator().Generate(operations, _backendVersion.ToString());
             Assert.AreEqual(3, statments.Count());
@@ -335,7 +365,7 @@ public void CreateTableOperation()
                 Assert.AreEqual("CREATE SCHEMA IF NOT EXISTS \"someSchema\"", statments.ElementAt(0).Sql);
             else
                 Assert.AreEqual("CREATE SCHEMA \"someSchema\"", statments.ElementAt(0).Sql);
-            Assert.AreEqual("CREATE TABLE \"someSchema\".\"someTable\"(\"SomeString\" varchar(233) NOT NULL,\"AnotherString\" text,\"SomeBytes\" bytea,\"SomeLong\" serial8,\"SomeDateTime\" timestamp)", statments.ElementAt(1).Sql);
+            Assert.AreEqual("CREATE TABLE \"someSchema\".\"someTable\"(\"SomeString\" varchar(233) NOT NULL DEFAULT '',\"AnotherString\" text,\"SomeBytes\" bytea,\"SomeLong\" serial8,\"SomeDateTime\" timestamp)", statments.ElementAt(1).Sql);
         }
 
         [Test]
diff --git a/EF6.PG/NpgsqlMigrationSqlGenerator.cs b/EF6.PG/NpgsqlMigrationSqlGenerator.cs
index c3f26e0..e41601a 100644
--- a/EF6.PG/NpgsqlMigrationSqlGenerator.cs
+++ b/EF6.PG/NpgsqlMigrationSqlGenerator.cs
@@ -292,6 +292,11 @@ protected virtual void Convert(AlterColumnOperation alterColumnOperation)
                         throw new NotImplementedException("Not supporting creating IsIdentity for " + alterColumnOperation.Column.Type);
                 }
             }
+            else if(alterColumnOperation.Column.IsNullable==false && alterColumnOperation.Column.ClrDefaultValue != null)
+            {
+                sql.Append(" SET DEFAULT ");
+                AppendValue(alterColumnOperation.Column.ClrDefaultValue, sql);
+            }
             else
                 sql.Append(" DROP DEFAULT");
             AddStatment(sql);
@@ -551,6 +556,11 @@ void AppendColumn(ColumnModel column, StringBuilder sql)
                     break;
                 }
             }
+            else if (column.IsNullable == false && column.ClrDefaultValue != null)
+            {
+                sql.Append(" DEFAULT ");
+                AppendValue(column.ClrDefaultValue, sql);
+            }            
         }
 
         void AppendColumnType(ColumnModel column, StringBuilder sql, bool setSerial)