Embodiments described herein relate to an apparatus, system, and method for controlling access to multiple antennas in a mobile device. The mobile device may determine priority among a first protocol stack associated with a first subscriber identity module (SIM) in the mobile device and a second protocol stack associated with a second SIM in the mobile device. The mobile device may lock control of a position of a switch to the first protocol stack based on determining the priority among the first protocol stack and the second protocol stack. The switch may control access to the multiple antennas. Accordingly, the second protocol stack may be unable to modify the position of the switch when control of the switch is locked to the first protocol stack.