"OnTriggerEnter2D" function is executed even if "Is Trigger" is disabled

I have the GameObject "player" with a box colider with the "Is Trigger" option unselected, ie it is not a trigger.

Inthescriptassociatedwiththeplayerthereisthe"OnTriggerEnter2D" function:

//...
void OnTriggerEnter2D (Collider2D o) {
    print(o.tag);
}

When the player collides with any object, it performs this function even though the box collider is not a trigger.

I no longer have any box collider associated with the player and I have no child objects.

I'm using Unity 5.2.2f1.