diff --git a/mcop_mt/threads_posix.cpp b/mcop_mt/threads_posix.cpp
index 06920b1..e3ae4d2 100644
--- a/mcop_mt/threads_posix.cpp
+++ b/mcop_mt/threads_posix.cpp
@@ -43,7 +43,7 @@
  * define this if you want to protect mutexes against being locked twice by
  * the same thread
  */
-#undef PTHREAD_DEBUG
+#undef PTHREAD_PREVENT_MULTI_LOCK
 
 namespace Arts {
 
@@ -58,7 +58,7 @@ protected:
 	friend class ThreadCondition_impl;
 	pthread_mutex_t mutex;
 
-#ifdef PTHREAD_DEBUG
+#ifdef PTHREAD_PREVENT_MULTI_LOCK
 	bool have_owner;
 	pthread_t owner;
 #endif
@@ -67,20 +67,20 @@ public:
 	Mutex_impl()
 	{
 		pthread_mutex_init(&mutex, 0);
-#ifdef PTHREAD_DEBUG
+#ifdef PTHREAD_PREVENT_MULTI_LOCK
 		have_owner = false;
 #endif
 	}
 	void lock()
 	{
-#ifdef PTHREAD_DEBUG
+#ifdef PTHREAD_PREVENT_MULTI_LOCK
 		pthread_t self = pthread_self();
 		arts_assert(!have_owner || !pthread_equal(owner, self));
 #endif
 
 		pthread_mutex_lock(&mutex);
 
-#ifdef PTHREAD_DEBUG
+#ifdef PTHREAD_PREVENT_MULTI_LOCK
 		arts_assert(!have_owner);
 		have_owner = true;
 		owner = self;
@@ -88,14 +88,14 @@ public:
 	}
 	bool tryLock()
 	{
-#ifdef PTHREAD_DEBUG
+#ifdef PTHREAD_PREVENT_MULTI_LOCK
 		pthread_t self = pthread_self();
 		arts_assert(!have_owner || !pthread_equal(owner, self));
 #endif
 
 		int result = pthread_mutex_trylock(&mutex);
 
-#ifdef PTHREAD_DEBUG
+#ifdef PTHREAD_PREVENT_MULTI_LOCK
 		if(result == 0)
 		{
 			arts_assert(!have_owner);
@@ -107,7 +107,7 @@ public:
 	}
 	void unlock()
 	{
-#ifdef PTHREAD_DEBUG
+#ifdef PTHREAD_PREVENT_MULTI_LOCK
 		arts_assert(have_owner && pthread_equal(owner, pthread_self()));
 		have_owner = false;
 #endif
@@ -137,7 +137,7 @@ public:
 		if(!have_owner || !pthread_equal(owner, self))
 		{
 			pthread_mutex_lock(&mutex);
-#ifdef PTHREAD_DEBUG
+#ifdef PTHREAD_PREVENT_MULTI_LOCK
 			arts_assert(count == 0);
 			arts_assert(!have_owner);
 #endif
@@ -155,7 +155,7 @@ public:
 			if(result != 0)
 				return false;
 
-#ifdef PTHREAD_DEBUG
+#ifdef PTHREAD_PREVENT_MULTI_LOCK
 			arts_assert(count == 0);
 			arts_assert(!have_owner);
 #endif
@@ -167,7 +167,7 @@ public:
 	}
 	void unlock()
 	{
-#ifdef PTHREAD_DEBUG
+#ifdef PTHREAD_PREVENT_MULTI_LOCK
 		arts_assert(have_owner && pthread_equal(owner, pthread_self()));
 		arts_assert(count > 0);
 #endif
@@ -234,7 +234,7 @@ public:
 		pthread_cond_broadcast(&cond);
 	}
 	void wait(Arts::Mutex_impl *mutex) {
-#ifdef PTHREAD_DEBUG
+#ifdef PTHREAD_PREVENT_MULTI_LOCK
 		pthread_t self = pthread_self();
 		arts_assert(((Mutex_impl *)mutex)->have_owner && pthread_equal(((Mutex_impl *)mutex)->owner, self));
 		((Mutex_impl *)mutex)->have_owner = false;
@@ -242,7 +242,7 @@ public:
 
 		pthread_cond_wait(&cond, &((Mutex_impl*)mutex)->mutex);
 
-#ifdef PTHREAD_DEBUG
+#ifdef PTHREAD_PREVENT_MULTI_LOCK
 		arts_assert(!((Mutex_impl *)mutex)->have_owner);
 		((Mutex_impl *)mutex)->have_owner = true;
 		((Mutex_impl *)mutex)->owner = self;