executor getIcon size problem

Hello,

I am developing a plugin for IDEA 12.1.4. There are an executor and programRunner defined under extensions section in plugin.xml:
    <extensions defaultExtensionNs="com.intellij">
        <executor implementation="com.ex.TestExecutor"/>
        <programRunner implementation="com.ex.TestRunner"/>
    </extensions>

Executor.getIcon() returns 16x16 sized image and it's is shown after the debug button on the action bar.

Everything works fine exept this entry appears in the idea.log file:

WARN - openapi.wm.impl.ToolWindowImpl - ToolWindow icons should be 13x13. Please fix icon path...

I've checked that original "run" and "debug" images and they also have 16x16 size.  How I can fix that?

Tried to define icon under action and trigger programRunner from there but with no luck. Is there any examples about this?