Index: src/libcfa/iostream.c
===================================================================
--- src/libcfa/iostream.c	(revision 9c313496292e447189530c6d9e91a7b120e46cc2)
+++ src/libcfa/iostream.c	(revision 06ccbc7c96f8bd0a8f66a7a54e38755a5299ee74)
@@ -203,4 +203,5 @@
 	os | arg | ", ";
 	os | rest;
+	return os;
 } // ?|?