diff --git a/include/nuttx/mutex.h b/include/nuttx/mutex.h
index e69017e807..1ad8bfe4ef 100644
--- a/include/nuttx/mutex.h
+++ b/include/nuttx/mutex.h
@@ -315,7 +315,7 @@ void nxmutex_reset(FAR mutex_t *mutex);
  *
  ****************************************************************************/
 
-int nxmutex_breaklock(FAR mutex_t *mutex, FAR bool *locked);
+int nxmutex_breaklock(FAR mutex_t *mutex, FAR unsigned int *locked);
 
 /****************************************************************************
  * Name: nxmutex_restorelock
@@ -334,7 +334,7 @@ int nxmutex_breaklock(FAR mutex_t *mutex, FAR bool *locked);
  *
  ****************************************************************************/
 
-int nxmutex_restorelock(FAR mutex_t *mutex, bool locked);
+int nxmutex_restorelock(FAR mutex_t *mutex, unsigned int locked);
 
 /****************************************************************************
  * Name: nxrmutex_init
diff --git a/libs/libc/misc/lib_mutex.c b/libs/libc/misc/lib_mutex.c
index e4e808d71c..3e3d8341f2 100644
--- a/libs/libc/misc/lib_mutex.c
+++ b/libs/libc/misc/lib_mutex.c
@@ -441,7 +441,7 @@ void nxmutex_reset(FAR mutex_t *mutex)
  *
  ****************************************************************************/
 
-int nxmutex_breaklock(FAR mutex_t *mutex, FAR bool *locked)
+int nxmutex_breaklock(FAR mutex_t *mutex, FAR unsigned int *locked)
 {
   int ret = OK;
 
@@ -475,7 +475,7 @@ int nxmutex_breaklock(FAR mutex_t *mutex, FAR bool *locked)
  *
  ****************************************************************************/
 
-int nxmutex_restorelock(FAR mutex_t *mutex, bool locked)
+int nxmutex_restorelock(FAR mutex_t *mutex, unsigned int locked)
 {
   return locked ? nxmutex_lock(mutex) : OK;
 }