diff --git a/flight/CopterControl/System/inc/pios_config.h b/flight/CopterControl/System/inc/pios_config.h
index 67328c0f8..4362dbca2 100644
--- a/flight/CopterControl/System/inc/pios_config.h
+++ b/flight/CopterControl/System/inc/pios_config.h
@@ -96,6 +96,7 @@
 #define PIOS_STABILIZATION_STACK_SIZE   624
 #define PIOS_TELEM_STACK_SIZE           500
 
+#define IDLE_COUNTS_PER_SEC_AT_NO_LOAD 1995998
 //#define PIOS_QUATERNION_STABILIZATION
 
 #endif /* PIOS_CONFIG_H */
diff --git a/flight/Modules/System/systemmod.c b/flight/Modules/System/systemmod.c
index 6c5a72d16..1cc3a6a5b 100644
--- a/flight/Modules/System/systemmod.c
+++ b/flight/Modules/System/systemmod.c
@@ -52,9 +52,12 @@
 // Private constants
 #define SYSTEM_UPDATE_PERIOD_MS 1000
 #define LED_BLINK_RATE_HZ 5
+
+#ifndef IDLE_COUNTS_PER_SEC_AT_NO_LOAD
 #define IDLE_COUNTS_PER_SEC_AT_NO_LOAD 995998	// calibrated by running tests/test_cpuload.c
 											  // must be updated if the FreeRTOS or compiler
 											  // optimisation options are changed.
+#endif
 
 #if defined(PIOS_MANUAL_STACK_SIZE)
 #define STACK_SIZE_BYTES PIOS_MANUAL_STACK_SIZE