Index: tests/Makefile.am
===================================================================
--- tests/Makefile.am	(revision a554e5f423752296e46ab9ced5a34d32676e55d5)
+++ tests/Makefile.am	(revision 454b4e01b75e00e1a232a34fc6777a3e01b733c2)
@@ -43,4 +43,5 @@
 	-g \
 	-Wall \
+	-Werror=return-type \
 	-Wno-unused-function \
 	-Wno-psabi \