diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8041cfb7d2..c43c45d8d4 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -14,6 +14,8 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
    - HVM PIRQs are disabled by default.
    - Reduce IOMMU setup time for hardware domain.
  - xl/libxl configures vkb=[] for HVM domains with priority over vkb_device.
+ - Increase the maximum number of CPUs Xen can be built for from 4095 to
+   16383.
 
 ### Added
  - On x86:
diff --git a/SUPPORT.md b/SUPPORT.md
index e10d46d924..d5d60c62ec 100644
--- a/SUPPORT.md
+++ b/SUPPORT.md
@@ -61,6 +61,11 @@ For the Cortex A77 r0p0 - r1p0, see Errata 1508412.
 
     Status, x86: Supported
 
+### Physical CPUs
+
+    Status, x86: Supported up to 4096
+    Status, ARM: Supported up to 128
+
 ### Host ACPI (via Domain 0)
 
     Status, x86 PV: Supported
diff --git a/xen/arch/Kconfig b/xen/arch/Kconfig
index 67ba38f32f..308ce129a8 100644
--- a/xen/arch/Kconfig
+++ b/xen/arch/Kconfig
@@ -6,7 +6,7 @@ config PHYS_ADDR_T_32
 
 config NR_CPUS
 	int "Maximum number of CPUs"
-	range 1 4095
+	range 1 16383
 	default "256" if X86
 	default "8" if ARM && RCAR3
 	default "4" if ARM && QEMU