diff --git a/core/mutex.c b/core/mutex.c
index 297c8513a5ac..a79426ed1b4d 100644
--- a/core/mutex.c
+++ b/core/mutex.c
@@ -120,7 +120,7 @@ void mutex_unlock(struct mutex_t *mutex)
 
 void mutex_unlock_and_sleep(struct mutex_t *mutex)
 {
-    DEBUG("%s: unlocking mutex. val: %u pid: %u, and take a nap\n", active_thread->name, mutex->val, thread_pid);
+    DEBUG("%s: unlocking mutex. val: %u pid: %u, and taking a nap\n", active_thread->name, mutex->val, thread_pid);
     int irqstate = disableIRQ();
 
     if (mutex->val != 0) {
diff --git a/tests/test_mutex_unlock_and_sleep/Makefile b/tests/test_mutex_unlock_and_sleep/Makefile
new file mode 100644
index 000000000000..2a99c8dfc8d7
--- /dev/null
+++ b/tests/test_mutex_unlock_and_sleep/Makefile
@@ -0,0 +1,4 @@
+export PROJECT = test_mutex_unlock_and_sleep
+include ../Makefile.tests_common
+
+include $(RIOTBASE)/Makefile.include
diff --git a/tests/test_mutex_unlock_and_sleep/main.c b/tests/test_mutex_unlock_and_sleep/main.c
new file mode 100644
index 000000000000..fe946c9c375c
--- /dev/null
+++ b/tests/test_mutex_unlock_and_sleep/main.c
@@ -0,0 +1,69 @@
+/*
+ * Copyright (C) 2014 Hamburg University of Applied Siences (HAW)
+ *
+ * This file is subject to the terms and conditions of the GNU Lesser General
+ * Public License. See the file LICENSE in the top level directory for more
+ * details.
+ */
+
+/**
+ * @ingroup tests
+ * @{
+ *
+ * @file
+ * @brief   simple test application for atomic mutex unlocking and sleeping
+ *
+ * @author  Martin Landsmann <martin.landsmann@haw-hamburg.de>
+ *
+ * @}
+ */
+
+#include <stdio.h>
+#include "thread.h"
+#include "mutex.h"
+
+static mutex_t mutex;
+static volatile int indicator, count;
+
+static char stack[KERNEL_CONF_STACKSIZE_MAIN];
+static void second_thread(void)
+{
+    while (1) {
+        mutex_lock(&mutex);
+        thread_wakeup(1);
+        indicator--;
+        mutex_unlock_and_sleep(&mutex);
+    }
+}
+
+int main(void)
+{
+    indicator = 0;
+    count = 0;
+    mutex_init(&mutex);
+
+    thread_create(stack,
+                  KERNEL_CONF_STACKSIZE_MAIN,
+                  PRIORITY_MAIN - 1,
+                  CREATE_WOUT_YIELD | CREATE_STACKTEST,
+                  second_thread,
+                  "second_thread");
+
+    while (1) {
+        mutex_lock(&mutex);
+        thread_wakeup(2);
+        indicator++;
+        count++;
+
+        if (indicator > 1 || indicator < -1) {
+            printf("Error, threads did not sleep properly. [indicator: %d]\n", indicator);
+            return -1;
+        }
+
+        if ((count % 100000) == 0) {
+            printf("Still alive alternated [count: %dk] times.\n", count / 1000);
+        }
+
+        mutex_unlock_and_sleep(&mutex);
+    }
+}