Index: configure.ac
==================================================================
--- configure.ac
+++ configure.ac
@@ -128,10 +128,17 @@
 		check_pedantic="no"
 
 		AC_SUBST(MAP_LDFLAGS, ['-Wl,-Map,$@.map'])
 		;;
 esac
+
+AS_IF([test x"$host_os" = x"msdosdjgpp" -a x"$build_os" = x"msdosdjgpp"], [
+	dnl Hack to make configure find these on DOS.
+	: ${AR:=ar.exe}
+	: ${GREP:=grep.exe}
+	: ${RANLIB:=ranlib.exe}
+])
 
 AC_LANG([Objective C])
 AC_PROG_OBJC([clang egcc gcc])
 AC_PROG_OBJCPP
 AC_PROG_LN_S