diff --git a/libraries/rtos/rtx/RTX_CM_lib.h b/libraries/rtos/rtx/RTX_CM_lib.h
index c7decba018..2a694e26ab 100755
--- a/libraries/rtos/rtx/RTX_CM_lib.h
+++ b/libraries/rtos/rtx/RTX_CM_lib.h
@@ -259,6 +259,9 @@ osThreadDef_t os_thread_def_main = {(os_pthread)main, osPriorityNormal, 0, NULL}
 #elif defined(TARGET_STM32F411RE)
 #define INITIAL_SP            (0x20020000UL)
 
+#elif defined(TARGET_STM32F103RB)
+#define INITIAL_SP            (0x20005000UL)
+
 #else
 #error "no target defined"
 
diff --git a/libraries/rtos/rtx/RTX_Conf_CM.c b/libraries/rtos/rtx/RTX_Conf_CM.c
index 97a050045d..35e4c114cf 100755
--- a/libraries/rtos/rtx/RTX_Conf_CM.c
+++ b/libraries/rtos/rtx/RTX_Conf_CM.c
@@ -53,7 +53,8 @@
 	 || defined(TARGET_KL46Z)   || defined(TARGET_STM32F407) || defined(TARGET_F407VG)  || defined(TARGET_STM32F303VC) || defined(TARGET_LPC1549) || defined(TARGET_LPC11U68) || defined(TARGET_NRF51822) || defined(TARGET_STM32F411RE)
 #    define OS_TASKCNT         14
 #  elif defined(TARGET_LPC11U24) || defined(TARGET_LPC11U35_401)  || defined(TARGET_LPC11U35_501) || defined(TARGET_LPCCAPPUCCINO) || defined(TARGET_LPC1114) \
-	 || defined(TARGET_LPC812)   || defined(TARGET_KL25Z)         || defined(TARGET_KL05Z)        || defined(TARGET_STM32F100RB)  || defined(TARGET_STM32F051R8)
+	 || defined(TARGET_LPC812)   || defined(TARGET_KL25Z)         || defined(TARGET_KL05Z)        || defined(TARGET_STM32F100RB)  || defined(TARGET_STM32F051R8) \
+	 || defined(TARGET_STM32F103RB)
 #    define OS_TASKCNT         6
 #  else
 #    error "no target defined"
@@ -66,7 +67,8 @@
 	 || defined(TARGET_KL46Z)   || defined(TARGET_STM32F407) || defined(TARGET_F407VG)  || defined(TARGET_STM32F303VC) || defined(TARGET_LPC1549) || defined(TARGET_LPC11U68) || defined(TARGET_NRF51822) || defined(TARGET_STM32F411RE)
 #      define OS_SCHEDULERSTKSIZE    256
 #  elif defined(TARGET_LPC11U24) || defined(TARGET_LPC11U35_401)  || defined(TARGET_LPC11U35_501) || defined(TARGET_LPCCAPPUCCINO)  || defined(TARGET_LPC1114) \
-	 || defined(TARGET_LPC812)   || defined(TARGET_KL25Z)         || defined(TARGET_KL05Z)        || defined(TARGET_STM32F100RB)  || defined(TARGET_STM32F051R8)
+	 || defined(TARGET_LPC812)   || defined(TARGET_KL25Z)         || defined(TARGET_KL05Z)        || defined(TARGET_STM32F100RB)  || defined(TARGET_STM32F051R8) \
+	 || defined(TARGET_STM32F103RB)
 #      define OS_SCHEDULERSTKSIZE    128
 #  else
 #    error "no target defined"
@@ -140,7 +142,10 @@
 #    define OS_CLOCK       84000000
 
 #  elif defined(TARGET_STM32F411RE)
-#     define OS_CLOCK       100000000
+#     define OS_CLOCK      100000000
+
+#elif defined(TARGET_STM32F103RB)
+#    define OS_CLOCK       72000000
 
 #  else
 #    error "no target defined"