diff --git a/radio/src/targets/simu/simpgmspace.h b/radio/src/targets/simu/simpgmspace.h
index 647c73115..1b150a7e8 100644
--- a/radio/src/targets/simu/simpgmspace.h
+++ b/radio/src/targets/simu/simpgmspace.h
@@ -396,7 +396,7 @@ extern OS_MutexID audioMutex;
 #define WDRF   0
 
 void * simuMain(void * args = NULL);
-extern uint8_t MCUCSR, MCUSR;
+extern uint8_t MCUCSR, MCUSR, MCUCR;
 
 typedef unsigned int       U32;
 typedef unsigned long long U64;