Validation error when providing numerical key-value parameters from Slack

When providing a numerical key-value parameters, e.g. diskspace some-host /var timeout=300, this results in a validation error. (Link to according section in the docs)

From st2api.log

ERROR aliasexecution [-] Unable to execute action. Parameter validation failed.
Traceback (most recent call last):
  File "/opt/stackstorm/st2/lib/python2.7/site-packages/st2api/controllers/v1/aliasexecution.py", line 163, in _schedule_execution
    _, action_execution_db = action_service.request(liveaction)
  File "/opt/stackstorm/st2/lib/python2.7/site-packages/st2common/services/action.py", line 148, in request
    liveaction, execution = create_request(liveaction)
  File "/opt/stackstorm/st2/lib/python2.7/site-packages/st2common/services/action.py", line 79, in create_request
    allow_default_none=True)
  File "/opt/stackstorm/st2/lib/python2.7/site-packages/st2common/util/schema/__init__.py", line 293, in validate
    jsonschema.validate(instance=instance, schema=schema, cls=cls, *args, **kwargs)
  File "/opt/stackstorm/st2/lib/python2.7/site-packages/jsonschema/validators.py", line 478, in validate
    cls(schema, *args, **kwargs).validate(instance)
  File "/opt/stackstorm/st2/lib/python2.7/site-packages/jsonschema/validators.py", line 123, in validate
    raise error
ValidationError: u'300' is not of type u'integer'

Failed validating u'type' in schema['properties'][u'timeout']:
    {u'default': 1500,
     u'description': u'Time to wait for the action to finish',
     u'type': u'integer'}

On instance[u'timeout']:
    u'300'

This is the according action (edit)alias:

---
name: "remote_diskspace"
description: "Run diskspace analysis on a remote server"
runner_type: local-shell-cmd
entry_point: ""
enabled: true
parameters:
  sudo:
    description: "Run command with sudo"
    type: boolean
    immutable: true
    default: true
  cmd:
    description: "Command to run"
    type: string
    immutable: true
    default: "export ANSIBLE_STDOUT_CALLBACK='json' && /opt/stackstorm/virtualenvs/ansible/bin/ansible-playbook -i /opt/ansible-action/cmdb_connect/dynamic_inventory.sh /opt/ansible-action/playbooks/diskspace.yaml --extra-vars='{\"hosts\":\"{{hosts|replace('http://','')}}\", \"folder\":\"{{folder|replace('\\\\','/')}}\"}'"
  hosts:
    description: "Ansible hosts"
    type: string
    required: true
  folder:
    description: "Folder to analyze"
    type: string
    required: true
  timeout:
    description: "Time to wait for the action to finish"
    default: 1500

ST2 version: st2 2.0.1