Default value is not removed when changing a column's type

CREATE TABLE customers (
  id INTEGER NOT NULL AUTO_INCREMENT PRIMARY KEY,
  customer_type enum('b2c','b2b') NOT NULL default 'b2c'
) AUTO_INCREMENT=1001;

alter table customers change customer_type customer_kind int;

connect_1    | org.apache.kafka.connect.errors.ConnectException: Invalid default value
connect_1    | 	at io.debezium.connector.mysql.AbstractReader.wrap(AbstractReader.java:200)
connect_1    | 	at io.debezium.connector.mysql.AbstractReader.failed(AbstractReader.java:178)
connect_1    | 	at io.debezium.connector.mysql.BinlogReader.handleEvent(BinlogReader.java:452)
connect_1    | 	at com.github.shyiko.mysql.binlog.BinaryLogClient.notifyEventListeners(BinaryLogClient.java:1055)
connect_1    | 	at com.github.shyiko.mysql.binlog.BinaryLogClient.listenForEventPackets(BinaryLogClient.java:913)
connect_1    | 	at com.github.shyiko.mysql.binlog.BinaryLogClient.connect(BinaryLogClient.java:559)
connect_1    | 	at com.github.shyiko.mysql.binlog.BinaryLogClient$7.run(BinaryLogClient.java:793)
connect_1    | 	at java.lang.Thread.run(Thread.java:748)
connect_1    | Caused by: org.apache.kafka.connect.errors.SchemaBuilderException: Invalid default value
connect_1    | 	at org.apache.kafka.connect.data.SchemaBuilder.defaultValue(SchemaBuilder.java:131)
connect_1    | 	at io.debezium.relational.TableSchemaBuilder.addField(TableSchemaBuilder.java:307)
connect_1    | 	at io.debezium.relational.TableSchemaBuilder.lambda$create$0(TableSchemaBuilder.java:103)
connect_1    | 	at java.util.ArrayList.forEach(ArrayList.java:1257)
connect_1    | 	at java.util.Collections$UnmodifiableCollection.forEach(Collections.java:1080)
connect_1    | 	at java.util.Collections$UnmodifiableCollection.forEach(Collections.java:1080)
connect_1    | 	at io.debezium.relational.TableSchemaBuilder.create(TableSchemaBuilder.java:94)
connect_1    | 	at io.debezium.connector.mysql.MySqlSchema.lambda$applyDdl$3(MySqlSchema.java:406)
connect_1    | 	at java.lang.Iterable.forEach(Iterable.java:75)
connect_1    | 	at io.debezium.connector.mysql.MySqlSchema.applyDdl(MySqlSchema.java:401)
connect_1    | 	at io.debezium.connector.mysql.BinlogReader.handleQueryEvent(BinlogReader.java:637)
connect_1    | 	at io.debezium.connector.mysql.BinlogReader.handleEvent(BinlogReader.java:436)
connect_1    | 	... 5 more
connect_1    | Caused by: org.apache.kafka.connect.errors.DataException: Invalid Java object for schema type INT32: class java.lang.String for field: "null"
connect_1    | 	at org.apache.kafka.connect.data.ConnectSchema.validateValue(ConnectSchema.java:242)
connect_1    | 	at org.apache.kafka.connect.data.ConnectSchema.validateValue(ConnectSchema.java:212)
connect_1    | 	at org.apache.kafka.connect.data.SchemaBuilder.defaultValue(SchemaBuilder.java:129)
connect_1    | 	... 16 more