diff --git a/os/rt/ports/ARMCMx/cmsis_os/cmsis_os.h b/os/rt/ports/ARMCMx/cmsis_os/cmsis_os.h
index 63a326636..23f12a0b6 100644
--- a/os/rt/ports/ARMCMx/cmsis_os/cmsis_os.h
+++ b/os/rt/ports/ARMCMx/cmsis_os/cmsis_os.h
@@ -338,7 +338,7 @@ const osTimerDef_t os_timer_def_##name = {                                  \
 /**
  * @brief   Define a Mutex.
  */
-#if defined (osObjectsExternal)
+#if defined(osObjectsExternal)
 #define osMutexDef(name) extern const osMutexDef_t os_mutex_def_##name
 #else
 #define osMutexDef(name)  const osMutexDef_t os_mutex_def_##name = {0}
@@ -352,7 +352,7 @@ const osTimerDef_t os_timer_def_##name = {                                  \
 /**
  * @brief   Define a Semaphore.
  */
-#if defined (osObjectsExternal)
+#if defined(osObjectsExternal)
 #define osSemaphoreDef(name)                                                \
   extern const osSemaphoreDef_t os_semaphore_def_##name
 #else                            // define the object
@@ -391,7 +391,7 @@ const osPoolDef_t os_pool_def_##name = {                                    \
 /**
  * @brief   Define a Message Queue.
  */
-#if defined (osObjectsExternal)
+#if defined(osObjectsExternal)
 #define osMessageQDef(name, queue_sz, type)                                 \
   extern const osMessageQDef_t os_messageQ_def_##name
 #else