diff --git a/documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc b/documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc
--- a/documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc
+++ b/documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc
@@ -827,3 +827,5 @@
 * `options DEBUG_VFS_LOCKS`: track lock acquisition points for lockmgr/vnode locks, expanding the amount of information displayed by `show lockedvnods` in DDB. This option has a measurable performance impact.
 * `options DEBUG_MEMGUARD`: a replacement for the man:malloc[9] kernel memory allocator that uses the VM system to detect reads or writes from allocated memory after free. Details may be found in man:memguard[9]. This option has a significant performance impact, but can be very helpful in debugging kernel memory corruption bugs.
 * `options DIAGNOSTIC`: enable additional, more expensive diagnostic tests along the lines of `options INVARIANTS`.
+* `options KASAN`: enable the Kernel Address Sanitizer. This enables compiler instrumentation which can be used to detect invalid memory accesses in the kernel, such as use-after-frees and buffer overflows. This largely supersedes `options DEBUG_MEMGUARD`. See man:kasan[9] for details, and for the currently supported platforms.
+* `options KMSAN`: enable the Kernel Memory Sanitizer. This enables compiler instrumentation which can be used to detect uses of uninitialized memory. See man:kmsan[9] for details, and for the currently supported platforms.