diff --git a/arch/amd64/include/cflags.json b/arch/amd64/include/cflags.json
index 5ef1b69..a252393 100644
--- a/arch/amd64/include/cflags.json
+++ b/arch/amd64/include/cflags.json
@@ -1,6 +1,7 @@
 {
 	"buildflags": {
 		"Cflags": [
+			"--sysroot=$JEHANNE",
 			"-fno-builtin",
 			"-fno-omit-frame-pointer",
 			"-fplan9-extensions",