diff --git a/README.Linux-aarch64 b/README.Linux-aarch64.md
similarity index 51%
rename from README.Linux-aarch64
rename to README.Linux-aarch64.md
index fd91fc2fe..20647d07c 100644
--- a/README.Linux-aarch64
+++ b/README.Linux-aarch64.md
@@ -1,9 +1,12 @@
-This file documents the port of Mercury to Linux on AArch64 (ARM64),
-i.e. the `aarch64*-linux*` configuration.
+Mercury on Linux / AArch64
+==========================
+
+This file documents the port of Mercury to Linux on AArch64 (ARM64)
+(i.e. the `aarch64*-linux*` configuration).
 
 Mercury should build and install "out-of-the-box" on Linux for AArch64.
 
-Low-level C grades using non-local gotos, i.e. asm_fast.*, do not work
+Low-level C grades using non-local gotos, i.e. `asm_fast.*`, do not work
 with GCC 9 or later. Non-PIC (position-independent code) actually does
 still work, but PIC is commonly the default.
-If you require a low-level C grade, please use a reg.* grade.
+If you require a low-level C grade, please use a `reg.*` grade.
diff --git a/README.md b/README.md
index f6c7f7f9e..5a1d4d75b 100644
--- a/README.md
+++ b/README.md
@@ -40,7 +40,8 @@ Specific information is contained in individual README files:
   * Supported operating systems
 
       * [Linux](README.Linux)
-        ([PPC](README.Linux-PPC),
+        ([AArch64](README.Linux-aarch64.md),
+        [PPC](README.Linux-PPC),
         [m68k](README.Linux-m68k))
       * [macOS](README.macOS.md)
       * [FreeBSD](README.FreeBSD.md)