diff --git a/uefi/src/proto/security/memory_protection.rs b/uefi/src/proto/security/memory_protection.rs
index 38c229547..84bfb48dd 100644
--- a/uefi/src/proto/security/memory_protection.rs
+++ b/uefi/src/proto/security/memory_protection.rs
@@ -6,9 +6,7 @@ use core::ops::Range;
 
 /// Protocol for getting and setting memory protection attributes.
 ///
-/// This corresponds to the `EFI_MEMORY_ATTRIBUTE_PROTOCOL` [proposal].
-///
-/// [proposal]: https://bugzilla.tianocore.org/show_bug.cgi?id=3519
+/// Corresponds to the C type `EFI_MEMORY_ATTRIBUTE_PROTOCOL`.
 #[repr(C)]
 #[unsafe_protocol("f4560cf6-40ec-4b4a-a192-bf1d57d0b189")]
 pub struct MemoryProtection {
@@ -43,9 +41,13 @@ impl MemoryProtection {
     /// If the attributes are not consistent within the region,
     /// [`Status::NO_MAPPING`] is returned.
     ///
+    /// Implementations typically require that the start and end of the memory
+    /// region are aligned to the [UEFI page size].
+    ///
     /// [`READ_PROTECT`]: MemoryAttribute::READ_PROTECT
     /// [`EXECUTE_PROTECT`]: MemoryAttribute::EXECUTE_PROTECT
     /// [`READ_ONLY`]: MemoryAttribute::READ_ONLY
+    /// [UEFI page size]: uefi::table::boot::PAGE_SIZE
     pub fn get_memory_attributes(
         &self,
         byte_region: Range<PhysicalAddress>,
@@ -63,9 +65,13 @@ impl MemoryProtection {
     /// The valid attributes to set are [`READ_PROTECT`],
     /// [`EXECUTE_PROTECT`], and [`READ_ONLY`].
     ///
+    /// Implementations typically require that the start and end of the memory
+    /// region are aligned to the [UEFI page size].
+    ///
     /// [`READ_PROTECT`]: MemoryAttribute::READ_PROTECT
     /// [`EXECUTE_PROTECT`]: MemoryAttribute::EXECUTE_PROTECT
     /// [`READ_ONLY`]: MemoryAttribute::READ_ONLY
+    /// [UEFI page size]: uefi::table::boot::PAGE_SIZE
     pub fn set_memory_attributes(
         &self,
         byte_region: Range<PhysicalAddress>,
@@ -80,9 +86,13 @@ impl MemoryProtection {
     /// The valid attributes to clear are [`READ_PROTECT`],
     /// [`EXECUTE_PROTECT`], and [`READ_ONLY`].
     ///
+    /// Implementations typically require that the start and end of the memory
+    /// region are aligned to the [UEFI page size].
+    ///
     /// [`READ_PROTECT`]: MemoryAttribute::READ_PROTECT
     /// [`EXECUTE_PROTECT`]: MemoryAttribute::EXECUTE_PROTECT
     /// [`READ_ONLY`]: MemoryAttribute::READ_ONLY
+    /// [UEFI page size]: uefi::table::boot::PAGE_SIZE
     pub fn clear_memory_attributes(
         &self,
         byte_region: Range<PhysicalAddress>,
diff --git a/uefi/src/table/boot.rs b/uefi/src/table/boot.rs
index f3d97eb5e..69ce11fb5 100644
--- a/uefi/src/table/boot.rs
+++ b/uefi/src/table/boot.rs
@@ -32,6 +32,12 @@ static IMAGE_HANDLE: GlobalImageHandle = GlobalImageHandle {
     handle: UnsafeCell::new(None),
 };
 
+/// Size in bytes of a UEFI page.
+///
+/// Note that this is not necessarily the processor's page size. The UEFI page
+/// size is always 4 KiB.
+pub const PAGE_SIZE: usize = 4096;
+
 /// Contains pointers to all of the boot services.
 ///
 /// # Accessing `BootServices`