diff --git a/hypervisor/arch/x86/guest/vmcall.c b/hypervisor/arch/x86/guest/vmcall.c
index 13ae5a880..04cb7d368 100644
--- a/hypervisor/arch/x86/guest/vmcall.c
+++ b/hypervisor/arch/x86/guest/vmcall.c
@@ -205,7 +205,7 @@ struct acrn_vm *parse_target_vm(struct acrn_vm *service_vm, uint64_t hcall_id, u
 
 static int32_t dispatch_hypercall(struct acrn_vcpu *vcpu)
 {
-	int32_t ret = -EINVAL;
+	int32_t ret = -ENOTTY;
 	struct acrn_vm *vm = vcpu->vm;
 	uint64_t guest_flags = get_vm_config(vm->vm_id)->guest_flags;  /* hypercall ID from guest */
 	uint64_t hcall_id = vcpu_get_gpreg(vcpu, CPU_REG_R8);  /* hypercall ID from guest */
@@ -237,7 +237,7 @@ static int32_t dispatch_hypercall(struct acrn_vcpu *vcpu)
 					((guest_flags & permission_flags) != 0UL)) {
 				ret = dispatch->handler(vcpu, vcpu->vm, param1, param2);
 			} else {
-				/* The vCPU is not allowed to invoke the given hypercall. Keep `ret` as -EINVAL and no
+				/* The vCPU is not allowed to invoke the given hypercall. Keep `ret` as -ENOTTY and no
 				 * further actions required.
 				 */
 			}
diff --git a/hypervisor/include/lib/errno.h b/hypervisor/include/lib/errno.h
index bc8c0db75..3d682c5c3 100644
--- a/hypervisor/include/lib/errno.h
+++ b/hypervisor/include/lib/errno.h
@@ -23,6 +23,10 @@
 #define ENODEV		19
 /** Indicates that argument is not valid. */
 #define EINVAL		22
+/** Indicates the operation is undefined. */
+#define ENOTTY		25
+/** Indicates the operation is obsoleted. */
+#define ENOSYS		38
 /** Indicates that timeout occurs. */
 #define ETIMEDOUT	110