diff --git a/hw/arm/virt-acpi-build.c b/hw/arm/virt-acpi-build.c
index 89cecdd8e68f8335aad2ce804b2ae8bc6e34879c..6888c7be58562428bf8df28cfd3a9084afa868bd 100644
--- a/hw/arm/virt-acpi-build.c
+++ b/hw/arm/virt-acpi-build.c
@@ -671,8 +671,7 @@ build_gtdt(GArray *table_data, BIOSLinker *linker, VirtMachineState *vms)
     acpi_table_begin(&table, table_data);
 
     /* CntControlBase Physical Address */
-    /* FIXME: invalid value, should be 0xFFFFFFFFFFFFFFFF if not impl. ? */
-    build_append_int_noprefix(table_data, 0, 8);
+    build_append_int_noprefix(table_data, 0xFFFFFFFFFFFFFFFF, 8);
     build_append_int_noprefix(table_data, 0, 4); /* Reserved */
     /*
      * FIXME: clarify comment:
@@ -697,7 +696,7 @@ build_gtdt(GArray *table_data, BIOSLinker *linker, VirtMachineState *vms)
     /* Non-Secure EL2 timer Flags */
     build_append_int_noprefix(table_data, irqflags, 4);
     /* CntReadBase Physical address */
-    build_append_int_noprefix(table_data, 0, 8);
+    build_append_int_noprefix(table_data, 0xFFFFFFFFFFFFFFFF, 8);
     /* Platform Timer Count */
     build_append_int_noprefix(table_data, 0, 4);
     /* Platform Timer Offset */