dub subpackage output to shared lib not working

[Tofu Ninja via Digitalmars-d-learn]

Trying to get a dub sub package to output as a shared lib but for 
some reason I can only get it to output as a static lib.

dub.json
---
{
	"name": "tofueng",
	"targetType": "executable",
	"targetPath" : "game",
	"sourcePaths": ["eng"],
	"importPaths": ["eng"],

	"dependencies": {
		"tofueng:test": "*",
	},
	"subPackages": [
		{
			"name": "test",
			"targetType": "dynamicLibrary",
			"targetPath" : "game/libs",
			"sourcePaths": ["com/test"],
			"importPaths": ["com/test"]
		}
	]
}
---

Get tofueng_test.lib instead of tofueng_test.dll. If I try to 
build the sub package directly it builds the dll. What am I doing 
wrong?