diff --git a/core/synchro.c b/core/synchro.c
index b004a9e..d485f32 100644
--- a/core/synchro.c
+++ b/core/synchro.c
@@ -6,21 +6,18 @@
 #include "list.h"
 #include "time.h"
 
-struct wait_queue *waitQueues = NULL;
 
 int mutexInit(struct mutex *m)
 {
-    uint32_t flags;
 
     m->owner = NULL;
     m->wait  = (struct wait_queue *)malloc(sizeof(struct wait_queue));
     if (!m->wait)
         return ENOMEM;
+
+    waitQueueInit(m->wait);
     list_init(m->wait->thread);
 
-    disable_IRQs(flags);
-    list_add_tail(waitQueues, m->wait);
-    restore_IRQs(flags);
 
     return 0;
 }
@@ -40,7 +37,7 @@ int mutexFree(struct mutex *m)
                        getCurrentThread());
             }
 #endif
-            list_delete(waitQueues, m->wait);
+            waitQueueFree(m->wait);
             free(m->wait);
         } else {
             ret = EBUSY;
@@ -76,7 +73,7 @@ int mutexUnlock(struct mutex *m)
 
     m->owner = NULL;
 
-    wake_up(m->wait);
+    wakeUp(m->wait);
 
     restore_IRQs(flags);
 
diff --git a/core/wait.c b/core/wait.c
index e2c6ab0..fa70157 100644
--- a/core/wait.c
+++ b/core/wait.c
@@ -3,7 +3,27 @@
 #include "list.h"
 #include "wait.h"
 
-int wake_up(struct wait_queue *wq)
+static struct wait_queue *waitQueues = NULL;
+
+int waitQueueInit(struct wait_queue *wq)
+{
+    uint32_t flags;
+    disable_IRQs(flags);
+    list_add_tail(waitQueues, wq);
+    restore_IRQs(flags);
+    return 0;
+}
+
+int waitQueueFree(struct wait_queue *wq)
+{
+    uint32_t flags;
+    disable_IRQs(flags);
+    list_delete(waitQueues, wq);
+    restore_IRQs(flags);
+    return 0;
+}
+
+int wakeUp(struct wait_queue *wq)
 {
     struct kthread *th;
     uint32_t flags;
diff --git a/core/wait.h b/core/wait.h
index f337733..bc2b4a8 100644
--- a/core/wait.h
+++ b/core/wait.h
@@ -16,9 +16,11 @@ struct wait_queue {
 #define DECLARE_WAITQUEUE(name)					\
 	struct wait_queue name = __WAITQUEUE_INITIALIZER(name)
 
+int waitQueueInit(struct wait_queue *);
+int waitQueueFree(struct wait_queue *);
 int wait(struct wait_queue *);
 int waitTimeout(struct wait_queue *wq, unsigned long msec);
-int wake_up(struct wait_queue *);
+int wakeUp(struct wait_queue *);
 
 #define wait_event(wq, condition)                                                             \
     do {                                                                                      \
diff --git a/tests/test.c b/tests/test.c
index fd76f81..6cff6a6 100644
--- a/tests/test.c
+++ b/tests/test.c
@@ -274,7 +274,9 @@ void wqThread(void *arg)
 {
     (void)arg;
     DECLARE_WAITQUEUE(test);
+    waitQueueInit(&test);
     assert(waitTimeout(&test, 1000) == 1);
+    waitQueueFree(&test);
     haveTimeout = 1;
 }