Index: libcfa/prelude/sync-builtins.cf
===================================================================
--- libcfa/prelude/sync-builtins.cf	(revision 679363c9dd74e91adb17e95394dbba54046399f4)
+++ libcfa/prelude/sync-builtins.cf	(revision 7768b8df58110d321b6431c9d8728f39b7d92f86)
@@ -436,4 +436,7 @@
 #endif
 
+_Bool __atomic_exchange_n(volatile _Bool *, _Bool, int);
+_Bool __atomic_exchange_1(volatile _Bool *, _Bool, int);
+void __atomic_exchange(volatile _Bool *, volatile _Bool *, volatile _Bool *, int);
 char __atomic_exchange_n(volatile char *, char, int);
 char __atomic_exchange_1(volatile char *, char, int);