No matching hardware interface found for 'hardware_interface/JointStateInterface' while loading interfaces

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I have a robot defined in a URDF file that I want to use in gazebo with ros-control.

The robot has multiple non-fixed joints, but I only want to control the wheels. The other non-fixed joints should move freely according to the movement of the wheels. For the wheels I need to write a transmission like so:

<transmission name="${prefix}_wheel_trans">
    <type>transmission_interface/SimpleTransmission</type>
    <actuator name="${prefix}_wheel_motor">
        <mechanicalReduction>1</mechanicalReduction>
    </actuator>
    <joint name="${prefix}_wheel_joint">
        <hardwareInterface>hardware_interface/VelocityJointInterface</hardwareInterface>
    </joint>
</transmission>

My question is, how do I write a transmission for the other non-fixed joints so that their state is published by the JointStateController? I tried the following:

<transmission name="${prefix}_something_trans">
    <type>transmission_interface/SimpleTransmission</type>
    <actuator name="${prefix}_something_motor">
        <mechanicalReduction>1</mechanicalReduction>
    </actuator>
    <joint name="${prefix}_something_joint">
        <hardwareInterface>hardware_interface/JointStateInterface</hardwareInterface>
    </joint>
</transmission>

But it results in the error No matching hardware interface found for 'hardware_interface/JointStateInterface' while loading interfaces for something_joint.