diff --git a/test/Makefile.win b/test/Makefile.win
index 4025ae2..96105b3 100644
--- a/test/Makefile.win
+++ b/test/Makefile.win
@@ -1,4 +1,4 @@
-OPT=/EHsc -I../xbyak /W4 -D_CRT_SECURE_NO_WARNINGS
+OPT=/EHsc -I../xbyak /W4 -D_CRT_SECURE_NO_WARNINGS -I ../
 ../xbyak/xbyak_mnemonic.h: ../gen/gen_code.exe ../gen/gen_avx512.exe
 	../gen/gen_code.exe > $@
 	../gen/gen_avx512.exe >> $@