diff --git a/right/src/slave_scheduler.c b/right/src/slave_scheduler.c
index f1af173..af3323e 100644
--- a/right/src/slave_scheduler.c
+++ b/right/src/slave_scheduler.c
@@ -7,10 +7,11 @@
 #include "i2c.h"
 #include "i2c_addresses.h"
 
-uint8_t previousSlaveId;
-uint8_t currentSlaveId;
 uint32_t I2cSchedulerCounter;
 
+static uint8_t previousSlaveId;
+static uint8_t currentSlaveId;
+
 uhk_slave_t Slaves[] = {
     { .init = UhkModuleSlaveDriver_Init, .update = UhkModuleSlaveDriver_Update, .perDriverId = UhkModuleDriverId_LeftKeyboardHalf },
     { .init = UhkModuleSlaveDriver_Init, .update = UhkModuleSlaveDriver_Update, .perDriverId = UhkModuleDriverId_LeftAddon        },