diff --git a/include/metalsvm/mailbox.h b/include/metalsvm/mailbox.h
index 9801a8d5..4dff4887 100644
--- a/include/metalsvm/mailbox.h
+++ b/include/metalsvm/mailbox.h
@@ -21,7 +21,7 @@
 #define __MAILBOX_H__
 
 #include <metalsvm/string.h>
-#include <metalsvm/tasks.h>
+#include <metalsvm/mailbox_types.h>
 #include <metalsvm/semaphore.h>
 
 #ifdef __cplusplus
@@ -29,14 +29,6 @@ extern "C" {
 #endif
 
 #define MAILBOX(name, type) 	\
-	typedef struct mailbox_##name { \
-		type buffer[MAILBOX_SIZE]; \
-		int wpos, rpos; \
-		sem_t mails; \
-		sem_t boxes; \
-		spinlock_t rlock, wlock; \
-	} mailbox_##name##_t; \
-	\
 	inline static int mailbox_##name##_init(mailbox_##name##_t* m) { \
 		if (BUILTIN_EXPECT(!m, 0)) \
 			return -1; \
@@ -106,6 +98,7 @@ extern "C" {
 		return 0; \
 	}\
 
+MAILBOX(wait_msg, wait_msg_t)
 MAILBOX(int32, int32_t)
 MAILBOX(int16, int16_t)
 MAILBOX(int8, int8_t)
diff --git a/include/metalsvm/mailbox_types.h b/include/metalsvm/mailbox_types.h
new file mode 100644
index 00000000..f4d09c64
--- /dev/null
+++ b/include/metalsvm/mailbox_types.h
@@ -0,0 +1,56 @@
+/* 
+ * Copyright 2010 Stefan Lankes, Chair for Operating Systems,
+ *                               RWTH Aachen University
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * This file is part of MetalSVM.
+ */
+
+#ifndef __MAILBOX_TYPES_H__
+#define __MAILBOX_TYPES_H__
+
+#include <metalsvm/semaphore_types.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef struct {
+	tid_t	id;
+	int32_t	result;
+} wait_msg_t;
+
+#define MAILBOX_TYPES(name, type) 	\
+	typedef struct mailbox_##name { \
+		type buffer[MAILBOX_SIZE]; \
+		int wpos, rpos; \
+		sem_t mails; \
+		sem_t boxes; \
+		spinlock_t rlock, wlock; \
+	} mailbox_##name##_t;
+
+MAILBOX_TYPES(wait_msg, wait_msg_t)
+MAILBOX_TYPES(int32, int32_t)
+MAILBOX_TYPES(int16, int16_t)
+MAILBOX_TYPES(int8, int8_t)
+MAILBOX_TYPES(uint32, uint32_t)
+MAILBOX_TYPES(uint16, uint16_t)
+MAILBOX_TYPES(uint8, uint8_t)
+MAILBOX_TYPES(ptr, void*)
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/include/metalsvm/semaphore.h b/include/metalsvm/semaphore.h
index 53cc3c6a..b0b524f6 100644
--- a/include/metalsvm/semaphore.h
+++ b/include/metalsvm/semaphore.h
@@ -21,22 +21,13 @@
 #define __SEMAPHORE_H__
 
 #include <metalsvm/string.h>
-#include <metalsvm/tasks.h>
+#include <metalsvm/semaphore_types.h>
 #include <metalsvm/spinlock.h>
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
-typedef struct {
-	unsigned int value;
-	tid_t queue[MAX_TASKS];
-	unsigned int pos;
-	spinlock_t lock;
-} sem_t;
-
-#define SEM_INIT(v) {v, {[0 ... MAX_TASKS-1] = MAX_TASKS}, 0, SPINLOCK_INIT}
-
 inline static int sem_init(sem_t* s, unsigned int v) {
 	unsigned int i;
 
diff --git a/include/metalsvm/semaphore_types.h b/include/metalsvm/semaphore_types.h
new file mode 100644
index 00000000..09298c62
--- /dev/null
+++ b/include/metalsvm/semaphore_types.h
@@ -0,0 +1,42 @@
+/* 
+ * Copyright 2010 Stefan Lankes, Chair for Operating Systems,
+ *                               RWTH Aachen University
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * This file is part of MetalSVM.
+ */
+
+#ifndef __SEMAPHORE_TYPES_H__
+#define __SEMAPHORE_TYPES_H__
+
+#include <metalsvm/spinlock_types.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef struct {
+	unsigned int value;
+	tid_t queue[MAX_TASKS];
+	unsigned int pos;
+	spinlock_t lock;
+} sem_t;
+
+#define SEM_INIT(v) {v, {[0 ... MAX_TASKS-1] = MAX_TASKS}, 0, SPINLOCK_INIT}	
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif