diff --git a/CHANGELOG.md b/CHANGELOG.md
index da6f5d2..4267e41 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,16 @@
 # Changelog
 
+## Unreleased
+
+### Bugfixes
+
+- Fixed value of `El23Attributes::XN`.
+
+### Improvements
+
+- Added `NT` and `CONTIGUOUS_OR_PROTECTED` bits to `El1Attributes` and `El23Attributes`.
+- Added `El23Attributes::USER_RES1`.
+
 ## 0.12.0
 
 ### Breaking changes
diff --git a/src/descriptor.rs b/src/descriptor.rs
index 6a7506b..8dc3954 100644
--- a/src/descriptor.rs
+++ b/src/descriptor.rs
@@ -152,9 +152,11 @@ bitflags! {
         const READ_ONLY     = 1 << 7;
         const ACCESSED      = 1 << 10;
         const NON_GLOBAL    = 1 << 11;
+        const NT            = 1 << 16;
         /// Guarded Page - indirect forward edge jumps expect an appropriate BTI landing pad.
         const GP            = 1 << 50;
         const DBM           = 1 << 51;
+        const CONTIGUOUS_OR_PROTECTED = 1 << 52;
         /// Privileged Execute-never.
         const PXN           = 1 << 53;
         /// Unprivileged Execute-never.
@@ -224,14 +226,17 @@ bitflags! {
         const INNER_SHAREABLE = 3 << 8;
 
         const NS            = 1 << 5;
+        const USER_RES1     = 1 << 6;
         const READ_ONLY     = 1 << 7;
         const ACCESSED      = 1 << 10;
         const NON_GLOBAL    = 1 << 11;
+        const NT            = 1 << 16;
         /// Guarded Page - indirect forward edge jumps expect an appropriate BTI landing pad.
         const GP            = 1 << 50;
         const DBM           = 1 << 51;
+        const CONTIGUOUS_OR_PROTECTED = 1 << 52;
         /// Execute-never.
-        const XN           = 1 << 53;
+        const XN           = 1 << 54;
 
         // Software flags in block and page descriptor entries.
         const SWFLAG_0 = 1 << 55;