diff --git a/TESTS/mbed_hal/stack_size_unification/main.cpp b/TESTS/mbed_hal/stack_size_unification/main.cpp
index 912630e399..23c84a4e7d 100644
--- a/TESTS/mbed_hal/stack_size_unification/main.cpp
+++ b/TESTS/mbed_hal/stack_size_unification/main.cpp
@@ -31,19 +31,11 @@ extern osThreadAttr_t _main_thread_attr;
 #endif
 extern uint32_t mbed_stack_isr_size;
 
-#if !defined(MBED_CONF_RTOS_PRESENT)
-#define EXPECTED_ISR_STACK_SIZE                  (4096)
-#else
-#define EXPECTED_ISR_STACK_SIZE                  (1024)
-#endif
+#define EXPECTED_ISR_STACK_SIZE                  (MBED_CONF_TARGET_BOOT_STACK_SIZE)
 
-#if defined(TARGET_NUCLEO_F070RB) || defined(TARGET_STM32F072RB) || defined(TARGET_TMPM46B) || defined(TARGET_TMPM066)
-#define EXPECTED_MAIN_THREAD_STACK_SIZE          (3072)
-#else
-#define EXPECTED_MAIN_THREAD_STACK_SIZE          (4096)
-#endif
+#define EXPECTED_MAIN_THREAD_STACK_SIZE          (MBED_CONF_RTOS_MAIN_THREAD_STACK_SIZE)
 
-#define EXPECTED_USER_THREAD_DEFAULT_STACK_SIZE  (4096)
+#define EXPECTED_USER_THREAD_DEFAULT_STACK_SIZE  (MBED_CONF_RTOS_THREAD_STACK_SIZE)
 
 #if ((MBED_RAM_SIZE - MBED_BOOT_STACK_SIZE) <= (EXPECTED_MAIN_THREAD_STACK_SIZE + EXPECTED_ISR_STACK_SIZE))
 #error [NOT_SUPPORTED] Insufficient stack for staci_size_unification tests
diff --git a/rtos/source/TARGET_CORTEX/mbed_lib.json b/rtos/source/TARGET_CORTEX/mbed_lib.json
index ed275722d8..8fe9e42620 100644
--- a/rtos/source/TARGET_CORTEX/mbed_lib.json
+++ b/rtos/source/TARGET_CORTEX/mbed_lib.json
@@ -76,6 +76,9 @@
         "STM32F072RB": {
             "main-thread-stack-size": 3072
         },
+        "TMPM46B": {
+            "main-thread-stack-size": 3072
+        },
         "NUVOTON": {
             "idle-thread-stack-size-debug-extra": 512
         }
diff --git a/targets/TARGET_TOSHIBA/mbed_rtx.h b/targets/TARGET_TOSHIBA/mbed_rtx.h
index 2835015067..2110efe8de 100644
--- a/targets/TARGET_TOSHIBA/mbed_rtx.h
+++ b/targets/TARGET_TOSHIBA/mbed_rtx.h
@@ -25,10 +25,6 @@
 #ifndef INITIAL_SP
 #define INITIAL_SP                        (0x20080000UL)
 #endif
-#ifdef MBED_CONF_RTOS_MAIN_THREAD_STACK_SIZE
-#undef MBED_CONF_RTOS_MAIN_THREAD_STACK_SIZE
-#endif
-#define MBED_CONF_RTOS_MAIN_THREAD_STACK_SIZE 3072
 
 #endif