Index: libcfa/src/bits/weakso_locks.cfa
===================================================================
--- libcfa/src/bits/weakso_locks.cfa	(revision 8cfa4ef35bdd51590fccd4a3080e4a6c57848f9a)
+++ libcfa/src/bits/weakso_locks.cfa	(revision 92b99582f2cac55ec8dec114c10fa83e9b366054)
@@ -25,5 +25,5 @@
 void unlock( blocking_lock & ) {}
 void on_notify( blocking_lock &, struct $thread * ) {}
-size_t on_wait( blocking_lock & ) {}
+size_t on_wait( blocking_lock & ) { return 0; }
 void on_wakeup( blocking_lock &, size_t ) {}
 size_t wait_count( blocking_lock & ) { return 0; }