--- a/GNUmakefile
+++ b/GNUmakefile
@@ -46,8 +46,10 @@ CFLAGS_OPT=-pipe $(WARN) $(DEFINE) $(OPT
 
 #CFLAGS=-pipe -Os -march=pentiumpro -mcpu=pentiumpro -fomit-frame-pointer -fschedule-insns2 -Wall
 
+# build time generators, native when cross compiling
+HOSTCC?=$(CC)
 ent: ent.c haveuint128.h headers
-	$(CC) -g -o ent ent.c -I.
+	$(HOSTCC) -g -o ent ent.c -I.
 
 # CFLAGS += -fstrict-aliasing -Wstrict-aliasing=2
 
@@ -1390,6 +1392,9 @@ Makefile: GNUmakefile dep libdep
 srcdirs=$(subst :, ,$(VPATH))
 srcfiles=$(foreach dir,$(srcdirs),$(wildcard $(dir)/*.c))
 
+json: json.c
+	$(HOSTCC) -o json json.c
+
 compile_commands.json.tmpl: json
 	./json $(srcfiles) > $@