diff --git a/sys/msdos/Makefile1.cross b/sys/msdos/Makefile1.cross
index a15a495ed..1cdc6d287 100644
--- a/sys/msdos/Makefile1.cross
+++ b/sys/msdos/Makefile1.cross
@@ -309,10 +309,10 @@ $(HOST_O)prereq.tag: $(INCL)/nhlua.h hobj.tag $(U)makedefs \
 $(INCL)/nhlua.h:
 	cd $(INCL); \
 	echo '/* nhlua.h - generated by Makefile1.cross */' > $@; \
-	echo '#include \"../lib/lua-5.3.5/src/lua.h\"' >> $@; \
+	echo '#include "../lib/lua-5.3.5/src/lua.h"' >> $@; \
 	sed -e '/(lua_error)/!d' -e '/(lua_error)/s/;/ NORETURN;/1' < $(LIB)/lua-5.3.5/src/lua.h >> $@; \
-	echo '#include \"../lib/lua-5.3.5/src/lualib.h\"' >> $@; \
-	echo '#include \"../lib/lua-5.3.5/src/lauxlib.h\"' >> $@; \
+	echo '#include "../lib/lua-5.3.5/src/lualib.h"' >> $@; \
+	echo '#include "../lib/lua-5.3.5/src/lauxlib.h"' >> $@; \
 	echo '/*nhlua.h*/' >> $@; \
 	cd $(SRC)