diff --git a/tests/test_mysql.py b/tests/test_mysql.py
index 2dc8838..7600ebf 100644
--- a/tests/test_mysql.py
+++ b/tests/test_mysql.py
@@ -1,4 +1,4 @@
-from sqlalchemy import Integer, func
+from sqlalchemy import Integer, func, Boolean
 from alembic.testing.fixtures import TestBase
 from alembic.testing import config
 from sqlalchemy import TIMESTAMP, MetaData, Table, Column, text
@@ -102,6 +102,17 @@ class MySQLOpTest(TestBase):
             'ALTER TABLE t ALTER COLUMN c DROP DEFAULT'
         )
+    def test_alter_column_remove_schematype(self):
+        context = op_fixture('mysql')
+        op.alter_column(
+            "t", "c",
+            type_=Integer,
+            existing_type=Boolean(create_constraint=True, name="ck1"),
+            server_default=None)
+        context.assert_(
+            'ALTER TABLE t MODIFY c INTEGER NULL'
+        )
+
     def test_alter_column_modify_default(self):
         context = op_fixture('mysql')
         # notice we dont need the existing type on this one...

#!
Traceback (most recent call last):
  File "/home/classic/dev/alembic/tests/test_mysql.py", line 111, in test_alter_column_remove_schematype
    server_default=None)
  File "<string>", line 8, in alter_column
  File "<string>", line 3, in alter_column
  File "/home/classic/dev/alembic/alembic/operations/ops.py", line 1414, in alter_column
    return operations.invoke(alt)
  File "/home/classic/dev/alembic/alembic/operations/base.py", line 318, in invoke
    return fn(self, operation)
  File "/home/classic/dev/alembic/alembic/operations/toimpl.py", line 41, in alter_column
    operations.impl.drop_constraint(constraint)
  File "/home/classic/dev/alembic/alembic/ddl/impl.py", line 183, in drop_constraint
    self._exec(schema.DropConstraint(const))
  File "/home/classic/dev/alembic/alembic/ddl/impl.py", line 118, in _exec
    return conn.execute(construct, *multiparams, **params)
  File "/home/classic/dev/alembic/alembic/testing/fixtures.py", line 151, in execute
    sql = text_type(stmt.compile(dialect=ctx_dialect))
  File "<string>", line 1, in <lambda>
  File "/home/classic/dev/sqlalchemy/lib/sqlalchemy/sql/elements.py", line 433, in compile
    return self._compiler(dialect, bind=bind, **kw)
  File "/home/classic/dev/sqlalchemy/lib/sqlalchemy/sql/ddl.py", line 26, in _compiler
    return dialect.ddl_compiler(dialect, self, **kw)
  File "/home/classic/dev/sqlalchemy/lib/sqlalchemy/sql/compiler.py", line 206, in __init__
    self.string = self.process(self.statement, **compile_kwargs)
  File "/home/classic/dev/sqlalchemy/lib/sqlalchemy/sql/compiler.py", line 229, in process
    return obj._compiler_dispatch(self, **kwargs)
  File "/home/classic/dev/sqlalchemy/lib/sqlalchemy/ext/compiler.py", line 423, in <lambda>
    lambda *arg, **kw: existing(*arg, **kw))
  File "/home/classic/dev/sqlalchemy/lib/sqlalchemy/ext/compiler.py", line 461, in __call__
    return fn(element, compiler, **kw)
  File "/home/classic/dev/alembic/alembic/ddl/mysql.py", line 312, in _mysql_drop_constraint
    "MySQL does not support CHECK constraints.")
NotImplementedError: MySQL does not support CHECK constraints.