diff --git a/tests/integration.rs b/tests/integration.rs
index bd28809d3..42fbcd404 100644
--- a/tests/integration.rs
+++ b/tests/integration.rs
@@ -5523,7 +5523,7 @@ mod tests {
             osdisk_path.push("windows-server-2019.raw");
 
             let mut child = Command::new(clh_command("cloud-hypervisor"))
-                .args(&["--cpus", "boot=2,kvm_hyperv=on,max_phys_bits=39"])
+                .args(&["--cpus", "boot=2,kvm_hyperv=on"])
                 .args(&["--memory", "size=4G"])
                 .args(&["--kernel", ovmf_path.to_str().unwrap()])
                 .args(&["--disk", &format!("path={}", osdisk_path.to_str().unwrap())])
@@ -5578,7 +5578,7 @@ mod tests {
 
             let mut child = Command::new(clh_command("cloud-hypervisor"))
                 .args(&["--api-socket", &api_socket])
-                .args(&["--cpus", "boot=2,kvm_hyperv=on,max_phys_bits=39"])
+                .args(&["--cpus", "boot=2,kvm_hyperv=on"])
                 .args(&["--memory", "size=4G"])
                 .args(&["--kernel", ovmf_path.to_str().unwrap()])
                 .args(&["--disk", &format!("path={}", osdisk_path.to_str().unwrap())])
diff --git a/vmm/src/memory_manager.rs b/vmm/src/memory_manager.rs
index 91ec67f34..2f94e12c7 100644
--- a/vmm/src/memory_manager.rs
+++ b/vmm/src/memory_manager.rs
@@ -255,11 +255,13 @@ const LENGTH_OFFSET_HIGH: u64 = 0xC;
 const STATUS_OFFSET: u64 = 0x14;
 const SELECTION_OFFSET: u64 = 0;
 
-// The MMIO address space size is subtracted with the size of a 4k page. This
-// is done on purpose to workaround a Linux bug when the VMM allocates devices
-// at the end of the addressable space.
+// The MMIO address space size is subtracted with 64k. This is done for the
+// following reasons:
+//  - Reduce the addressable space size by at least 4k to workaround a Linux
+//    bug when the VMM allocates devices at the end of the addressable space
+//  - Windows requires the addressable space size to be 64k aligned
 fn mmio_address_space_size(phys_bits: u8) -> u64 {
-    (1 << phys_bits) - 0x1000
+    (1 << phys_bits) - (1 << 16)
 }
 
 impl BusDevice for MemoryManager {
@@ -609,6 +611,10 @@ impl MemoryManager {
         let boot_guest_memory = guest_memory.clone();
 
         let mmio_address_space_size = mmio_address_space_size(phys_bits);
+        debug_assert_eq!(
+            (((mmio_address_space_size) >> 16) << 16),
+            mmio_address_space_size
+        );
         let end_of_device_area = GuestAddress(mmio_address_space_size - 1);
 
         let mut start_of_device_area =