diff --git a/src/thread/wiiu/SDL_syssem.c b/src/thread/wiiu/SDL_syssem.c
new file mode 100644
index 000000000..c923673e6
--- /dev/null
+++ b/src/thread/wiiu/SDL_syssem.c
@@ -0,0 +1,145 @@
+/*
+  Simple DirectMedia Layer
+  Copyright (C) 1997-2018 Sam Lantinga <slouken@libsdl.org>
+
+  This software is provided 'as-is', without any express or implied
+  warranty.  In no event will the authors be held liable for any damages
+  arising from the use of this software.
+
+  Permission is granted to anyone to use this software for any purpose,
+  including commercial applications, and to alter it and redistribute it
+  freely, subject to the following restrictions:
+
+  1. The origin of this software must not be misrepresented; you must not
+     claim that you wrote the original software. If you use this software
+     in a product, an acknowledgment in the product documentation would be
+     appreciated but is not required.
+  2. Altered source versions must be plainly marked as such, and must not be
+     misrepresented as being the original software.
+  3. This notice may not be removed or altered from any source distribution.
+*/
+#include "../../SDL_internal.h"
+
+#if SDL_THREAD_WIIU
+
+#include "SDL_timer.h"
+#include "SDL_thread.h"
+#include "SDL_systhread_c.h"
+
+#include <coreinit/semaphore.h>
+#include <coreinit/condition.h>
+#include <coreinit/alarm.h>
+#include <coreinit/mutex.h>
+#include <coreinit/time.h>
+
+#include <stdbool.h>
+
+typedef struct
+{
+   OSCondition *cond;
+   bool timed_out;
+} WIIU_SemWaitTimeoutData;
+
+struct SDL_semaphore
+{
+	OSMutex mtx;
+	OSSemaphore sem;
+	OSCondition cond;
+};
+
+SDL_sem *
+SDL_CreateSemaphore(Uint32 initial_value)
+{
+    SDL_sem *sem;
+
+    sem = (SDL_sem *) SDL_malloc(sizeof(*sem));
+    if (sem) {
+        OSInitSemaphore(&sem->sem, initial_value);
+		OSInitMutex(&sem->mtx);
+		OSInitCond(&sem->cond);
+    } else {
+        SDL_OutOfMemory();
+    }
+
+    return sem;
+}
+
+void
+SDL_DestroySemaphore(SDL_sem * sem)
+{
+    if (sem) {
+        SDL_free(sem);
+    }
+}
+
+int
+SDL_SemTryWait(SDL_sem * sem)
+{
+    return (OSTryWaitSemaphore(&sem->sem) > 0) ? 0 : SDL_MUTEX_TIMEDOUT;
+}
+
+static void
+SDL_SemWaitTimeoutCallback(OSAlarm *alarm, OSContext *context)
+{
+   WIIU_SemWaitTimeoutData *data = (WIIU_SemWaitTimeoutData *)OSGetAlarmUserData(alarm);
+   data->timed_out = true;
+   OSSignalCond(data->cond);
+}
+
+int
+SDL_SemWaitTimeout(SDL_sem * sem, Uint32 ms)
+{
+	WIIU_SemWaitTimeoutData data;
+
+	// timeout is zero
+	if (!ms)
+		SDL_SemTryWait(sem);
+
+	OSLockMutex(&sem->mtx);
+
+	// setup callback data
+	data.timed_out = false;
+	data.cond = &sem->cond;
+
+	// set an alarm
+	OSAlarm alarm;
+	OSCreateAlarm(&alarm);
+	OSSetAlarmUserData(&alarm, &data);
+	OSSetAlarm(&alarm, OSMillisecondsToTicks(ms), &SDL_SemWaitTimeoutCallback);
+
+	// try to acquire the semaphore 
+    while((OSTryWaitSemaphore(&sem->sem) <= 0) && (data.timed_out == false)) {
+		OSWaitCond(&sem->cond, &sem->mtx);
+    }
+
+	OSCancelAlarm(&alarm);
+
+	OSUnlockMutex(&sem->mtx);
+
+    return (data.timed_out == false) ? 0 : SDL_MUTEX_TIMEDOUT;
+}
+
+int
+SDL_SemWait(SDL_sem * sem)
+{
+    OSWaitSemaphore(&sem->sem);
+    return 0;
+}
+
+Uint32
+SDL_SemValue(SDL_sem * sem)
+{
+    return OSGetSemaphoreCount(&sem->sem);
+}
+
+int
+SDL_SemPost(SDL_sem * sem)
+{
+	OSSignalSemaphore(&sem->sem);
+	OSSignalCond(&sem->cond);
+    return 0;
+}
+
+#endif /* SDL_THREAD_WIIU */
+
+/* vi: set ts=4 sw=4 expandtab: */