tinyint(1) with default value in schema.yml generates blank default value, gives SQLSTATE[42000]

doing a
doctrine:build --all --and-load
with a schema.yml of

Foo:
tableName: foo
options:
charset: utf8
columns:
bar:
type: tinyint(1)
default: 0

results in a blank value generated for the default keyword, and the following error:

SQLSTATE[42000]: Syntax error or access violation: 1064 You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ' PRIMARY KEY(id)) DEFAULT CHARACTER SET utf8 ENGINE = INNODB' at line 1. Failing Query: "CREATE TABLE foo (id BIGINT AUTO_INCREMENT, bar tinyint(1) DEFAULT , PRIMARY KEY(id)) DEFAULT CHARACTER SET utf8 ENGINE = INNODB". Failing Query: CREATE TABLE foo (id BIGINT AUTO_INCREMENT, bar tinyint(1) DEFAULT , PRIMARY KEY(id)) DEFAULT CHARACTER SET utf8 ENGINE = INNODB

I've also tried combinations of tinyint, tinyint(4), single-quoting the default value, and different default values.

Changing the type to int makes the issue disappear