Index: ruby/Makefile.am
===================================================================
--- ruby/Makefile.am.orig
+++ ruby/Makefile.am
@@ -12,7 +12,7 @@ TESTS = test
 endif
 endif
 
-CFLAGS += -Wno-strict-prototypes -Wno-missing-prototypes
+AM_CFLAGS = -Wno-strict-prototypes -Wno-missing-prototypes
 
 caca_la_CPPFLAGS = -I$(top_srcdir)/caca -I../caca $(RUBY_CFLAGS)
 caca_la_SOURCES = caca.c \