diff --git a/libraries/rtos/rtx/TARGET_CORTEX_M/RTX_Conf_CM.c b/libraries/rtos/rtx/TARGET_CORTEX_M/RTX_Conf_CM.c
index af69c9cde9..0ff3fd04f1 100755
--- a/libraries/rtos/rtx/TARGET_CORTEX_M/RTX_Conf_CM.c
+++ b/libraries/rtos/rtx/TARGET_CORTEX_M/RTX_Conf_CM.c
@@ -160,7 +160,7 @@
 #    define OS_CLOCK       168000000
 
 #elif defined(TARGET_STM32F302R8)
-#    define OS_CLOCK       64000000
+#    define OS_CLOCK       72000000
 
 #elif defined(TARGET_STM32L053R8) || defined(TARGET_STM32L053C8)
 #    define OS_CLOCK       32000000
diff --git a/libraries/tests/rtos/mbed/mutex/main.cpp b/libraries/tests/rtos/mbed/mutex/main.cpp
index 80d49a189c..b9c3352b4b 100644
--- a/libraries/tests/rtos/mbed/mutex/main.cpp
+++ b/libraries/tests/rtos/mbed/mutex/main.cpp
@@ -12,6 +12,8 @@
  */
 #if defined(TARGET_STM32L053R8) || defined(TARGET_STM32L053C8)
     #define STACK_SIZE DEFAULT_STACK_SIZE/4
+#elif defined(TARGET_STM32F334R8) && defined(TOOLCHAIN_IAR)
+    #define STACK_SIZE DEFAULT_STACK_SIZE/4	
 #else
     #define STACK_SIZE DEFAULT_STACK_SIZE
 #endif
diff --git a/libraries/tests/rtos/mbed/semaphore/main.cpp b/libraries/tests/rtos/mbed/semaphore/main.cpp
index 1f35e9f473..5d152a5485 100644
--- a/libraries/tests/rtos/mbed/semaphore/main.cpp
+++ b/libraries/tests/rtos/mbed/semaphore/main.cpp
@@ -13,6 +13,8 @@
  */
 #if defined(TARGET_STM32L053R8) || defined(TARGET_STM32L053C8)
     #define STACK_SIZE DEFAULT_STACK_SIZE/4
+#elif defined(TARGET_STM32F334R8) && (defined(TOOLCHAIN_GCC) || defined(TOOLCHAIN_IAR))
+    #define STACK_SIZE DEFAULT_STACK_SIZE/4
 #else
     #define STACK_SIZE DEFAULT_STACK_SIZE
 #endif