protocol: Specify that kernel must be physically contiguous
diff --git a/PROTOCOL.md b/PROTOCOL.md
index 1770c79d..7ab3298a 100644
--- a/PROTOCOL.md
+++ b/PROTOCOL.md
@@ -90,7 +90,8 @@ At handoff, the kernel will be properly loaded and mapped with appropriate
MMU permissions at the requested virtual memory address (provided it is at
or above `0xffffffff80000000`).
-No specific physical memory placement is guaranteed. In order to determine
+No specific physical memory placement is guaranteed, except that the kernel
+is guaranteed to be physically contiguous. In order to determine
where the kernel is loaded in physical memory, see the Kernel Address feature
below.
