Index: man/Makefile.in
--- man/Makefile.in.orig
+++ man/Makefile.in
@@ -1007,7 +1007,7 @@ uninstall-man: uninstall-man3 uninstall-man5 uninstall
 
 
 $(MANS_CPP): $(MANS_CPP:%=%.pre)
-	$(CPP_FOR_BUILD) -nostdinc -w -C -P -I$(top_srcdir)/man $@.pre $@
+	$(CPP_FOR_BUILD) -nostdinc -w -C -P -I$(top_srcdir)/man < $@.pre > $@
 
 # Tell versions [3.59,3.63) of GNU make to not export all variables.
 # Otherwise a system limit (for SysV at least) may be exceeded.