diff --git a/docs/specs/acpi_cpu_hotplug.txt b/docs/specs/acpi_cpu_hotplug.txt
index 5dec0c5010..f6f577457d 100644
--- a/docs/specs/acpi_cpu_hotplug.txt
+++ b/docs/specs/acpi_cpu_hotplug.txt
@@ -10,7 +10,7 @@ ACPI GPE block (IO ports 0xafe0-0xafe3, byte access):
 Generic ACPI GPE block. Bit 2 (GPE.2) used to notify CPU
 hot-add/remove event to ACPI BIOS, via SCI interrupt.
 
-CPU present bitmap (IO port 0xaf00-0xae1f, 1-byte access):
+CPU present bitmap (IO port 0xaf00-0xaf1f, 1-byte access):
 ---------------------------------------------------------------
 One bit per CPU. Bit position reflects corresponding CPU APIC ID.
 Read-only.