diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index 75f6ca0877f6..6d8d58056362 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -474,8 +474,8 @@ struct arm_smmu_cfg {
 };
 #define INVALID_IRPTNDX			0xff
 
-#define ARM_SMMU_CB_ASID(cfg)		((cfg)->cbndx)
-#define ARM_SMMU_CB_VMID(cfg)		((cfg)->cbndx + 1)
+#define ARM_SMMU_CB_ASID(cfg)		((cfg)->cbndx + 1)
+#define ARM_SMMU_CB_VMID(cfg)		((cfg)->cbndx + 2)
 
 struct arm_smmu_domain {
 	struct arm_smmu_device		*smmu;