--- glibc-2.20/stdlib/Makefile.ldbl~	2014-09-08 21:30:48.771678525 +0200
+++ glibc-2.20/stdlib/Makefile	2014-09-08 21:34:51.842639720 +0200
@@ -125,9 +125,16 @@ test-canon-ARGS = --test-dir=${common-ob
 
 bug-fmtmsg1-ENV = SEV_LEVEL=foo,11,newsev
 
+isomac-includes = -I../include $(+sysdep-includes) $(sysincludes) -I..
+ifeq (powerpc:8, $(base-machine):$(sizeof-long-double))
+# XXX only necessary for bootstrapping...
+isomac-includes += -I../libio -I../stdlib -I../wcsmbs
+endif
+
 $(objpfx)isomac.out: $(objpfx)isomac
 	$(dir $<)$(notdir $<) '$(CC)'  \
 	'-I../include $(+sysdep-includes) $(sysincludes) -I..' > $<.out; \
+	'$(isomac-includes)' > $<.out \
 	$(evaluate-test)
 
 isomac-CFLAGS = -O