diff --git a/headers/posix/setjmp.h b/headers/posix/setjmp.h
index adb1555929..49612b0337 100644
--- a/headers/posix/setjmp.h
+++ b/headers/posix/setjmp.h
@@ -29,6 +29,14 @@ extern void	_longjmp(jmp_buf jumpBuffer, int value);
 extern void	longjmp(jmp_buf jumpBuffer, int value);
 extern void	siglongjmp(sigjmp_buf jumpBuffer, int value);
 
+// ToDo: this is a temporary workaround for a bug in BeOS
+//	(it exports setjmp/sigsetjmp functions that do not work)
+#ifdef COMPILE_FOR_R5
+#	define setjmp(buffer) __sigsetjmp((buffer), 0)
+#	define sigsetjmp(buffer, mask) __sigsetjmp((buffer), (mask))
+extern int __sigsetjmp(jmp_buf buffer, int saveMask);
+#endif
+
 #ifdef __cplusplus
 }
 #endif