--- squid-3.5.26.orig/src/Makefile.am	2017-06-01 15:49:00.000000000 +0200
+++ squid-3.5.26/src/Makefile.am	2017-06-13 02:16:52.592883945 +0200
@@ -968,7 +968,7 @@ cache_cf.o: cf_parser.cci
 
 # cf_gen builds the configuration files.
 cf_gen$(EXEEXT): $(cf_gen_SOURCES) $(cf_gen_DEPENDENCIES) cf_gen_defines.cci
-	$(BUILDCXX) $(BUILDCXXFLAGS) -o $@ $(srcdir)/cf_gen.cc -I$(srcdir) -I$(top_builddir)/include/ -I$(top_builddir)/src
+	$(CXX_FOR_BUILD) $(CXXFLAGS_FOR_BUILD) -o $@ $(srcdir)/cf_gen.cc -I$(srcdir) -I$(top_builddir)/include/ -I$(top_builddir)/src
 
 # squid.conf.default is built by cf_gen when making cf_parser.cci
 squid.conf.default squid.conf.documented: cf_parser.cci