JBoss EAP 6 CLI module command inside an if/then executes even when the if statement resolves in false

Issue

I'm trying to accomplish the following JBoss cli script:

if (outcome == failed) of /system-property=jsf-2.2.7/:read-resource
    /system-property=jsf-2.2.7/:add(value=1)
    module add --name=javax.faces.api --slot=mojarra-2.2.7 --resources=src/main/resources/jsf-module/jsf-api-2.2.7.jar --module-xml=src/main/resources/jsf-module/mojarra-api-module.xml
end-if

However, even when the system-property=jsf-2.2.7 is already set, the module add is still executed, which should not be the case. In other words, even when the if conditional should return false, the command module is executed.