diff --git a/xen/arch/arm/psci.c b/xen/arch/arm/psci.c
index d800cb6..dede0e1 100644
--- a/xen/arch/arm/psci.c
+++ b/xen/arch/arm/psci.c

@@ -22,6 +22,7 @@
 #include <xen/mm.h>
 #include <xen/smp.h>
 #include <asm/psci.h>
+#include <asm/acpi.h>
 
 /*
  * While a 64-bit OS can make calls with SMC32 calling conventions, for

@@ -86,6 +87,9 @@ int __init psci_init_0_1(void)
     int ret;
     const struct dt_device_node *psci;
 
+    if ( !acpi_disabled )
+        return -EINVAL;