Index: libcfa/src/concurrency/clib/cfathread.cfa
===================================================================
--- libcfa/src/concurrency/clib/cfathread.cfa	(revision d971c8d1dfe6d5d040af4d236c91d2b9415adb40)
+++ libcfa/src/concurrency/clib/cfathread.cfa	(revision 304de00717ef6362ebb9fec97808ec4a0cdc837c)
@@ -245,7 +245,11 @@
 	int cfathread_mutex_init(cfathread_mutex_t *restrict mut, const cfathread_mutexattr_t *restrict) __attribute__((nonnull (1))) { *mut = new(); return 0; }
 	int cfathread_mutex_destroy(cfathread_mutex_t *mut) __attribute__((nonnull (1))) { delete( *mut ); return 0; }
-	int cfathread_mutex_lock   (cfathread_mutex_t *mut) __attribute__((nonnull (1))) { lock    ( (*mut)->impl ); return 0; }
-	int cfathread_mutex_trylock(cfathread_mutex_t *mut) __attribute__((nonnull (1))) { try_lock( (*mut)->impl ); return 0; }
-	int cfathread_mutex_unlock (cfathread_mutex_t *mut) __attribute__((nonnull (1))) { unlock  ( (*mut)->impl ); return 0; }
+	int cfathread_mutex_lock   (cfathread_mutex_t *mut) __attribute__((nonnull (1))) { lock( (*mut)->impl ); return 0; }
+	int cfathread_mutex_unlock (cfathread_mutex_t *mut) __attribute__((nonnull (1))) { unlock( (*mut)->impl ); return 0; }
+	int cfathread_mutex_trylock(cfathread_mutex_t *mut) __attribute__((nonnull (1))) {
+		bool ret = try_lock( (*mut)->impl );
+		if( ret ) return 0;
+		else return EBUSY;
+	}
 
 	//--------------------