Index: libcfa/src/bits/queue.hfa
===================================================================
--- libcfa/src/bits/queue.hfa	(revision 1f6623cc5ccfb6fc3081e1e36443d8845caab60a)
+++ libcfa/src/bits/queue.hfa	(revision 10b5970650e2ff3d8e757dd5c91889d466e44fe0)
@@ -33,8 +33,10 @@
 		}
 
-		T * succ( Queue(T) & q, T * n ) with( q ) {		// pre: *n in *q
-			#ifdef __CFA_DEBUG__
+		T * succ( Queue(T) & q, T * n ) {					// pre: *n in *q
+		  #ifdef __CFA_DEBUG__
 			if ( ! listed( n ) ) abort( "(Queue &)%p.succ( %p ) : Node is not on a list.", &q, n );
-			#endif // __CFA_DEBUG__
+		  #else
+			(void) q;
+		  #endif // __CFA_DEBUG__
 			return (Next( n ) == n) ? 0p : Next( n );
 		} // post: n == tail() & succ(n) == 0 | n != tail() & *succ(n) in *q
Index: libcfa/src/concurrency/mutex_stmt.hfa
===================================================================
--- libcfa/src/concurrency/mutex_stmt.hfa	(revision 1f6623cc5ccfb6fc3081e1e36443d8845caab60a)
+++ libcfa/src/concurrency/mutex_stmt.hfa	(revision 10b5970650e2ff3d8e757dd5c91889d466e44fe0)
@@ -30,5 +30,5 @@
 forall(L & | is_lock(L)) {
     static inline void * __get_mutexstmt_lock_ptr( L & this ) { return &this; }
-    static inline L __get_mutexstmt_lock_type( L & this ) {}
-    static inline L __get_mutexstmt_lock_type( L * this ) {}
+    static inline L __get_mutexstmt_lock_type( L & ) {}
+    static inline L __get_mutexstmt_lock_type( L * ) {}
 }