diff --git a/paw/stos/head/arch/amd64/vas.h b/paw/stos/head/arch/amd64/vas.h
index d34e756..900e19b 100644
--- a/paw/stos/head/arch/amd64/vas.h
+++ b/paw/stos/head/arch/amd64/vas.h
@@ -20,4 +20,8 @@ typedef struct {
     UPTR Cr3;
 } MMU_VAS;
 
+/* Obtain the VAS base */
+#define VAS_BASE(VAS_P) \
+    (VAS_P)->Cr3
+
 #endif  /* !_MACHINE_VAS_H_ */