diff --git a/osal/FreeRTOS/Clock.cpp b/osal/FreeRTOS/Clock.cpp
index d1c9f97b..dce20265 100644
--- a/osal/FreeRTOS/Clock.cpp
+++ b/osal/FreeRTOS/Clock.cpp
@@ -2,10 +2,8 @@
 #include <framework/globalfunctions/timevalOperations.h>
 #include <framework/osal/FreeRTOS/Timekeeper.h>
 
-extern "C" {
 #include <freertos/FreeRTOS.h>
 #include <freertos/task.h>
-}
 
 #include <stdlib.h>
 #include <time.h>
@@ -14,7 +12,7 @@ extern "C" {
 //TODO much of this code can be reused for tick-only systems
 
 uint16_t Clock::leapSeconds = 0;
-MutexIF* Clock::timeMutex = NULL;
+MutexIF* Clock::timeMutex = nullptr;
 
 uint32_t Clock::getTicksPerSecond(void) {
 	return 1000;
@@ -131,7 +129,7 @@ ReturnValue_t Clock::convertTimevalToJD2000(timeval time, double* JD2000) {
 
 ReturnValue_t Clock::convertUTCToTT(timeval utc, timeval* tt) {
 	//SHOULDDO: works not for dates in the past (might have less leap seconds)
-	if (timeMutex == NULL) {
+	if (timeMutex == nullptr) {
 		return HasReturnvaluesIF::RETURN_FAILED;
 	}
 
diff --git a/osal/FreeRTOS/Timekeeper.h b/osal/FreeRTOS/Timekeeper.h
index 8709e362..7d3ca22b 100644
--- a/osal/FreeRTOS/Timekeeper.h
+++ b/osal/FreeRTOS/Timekeeper.h
@@ -2,10 +2,9 @@
 #define FRAMEWORK_OSAL_FREERTOS_TIMEKEEPER_H_
 
 #include <framework/timemanager/Clock.h>
-extern "C" {
+
 #include <freertos/FreeRTOS.h>
 #include <freertos/task.h>
-}
 
 
 /**