Index: docs/LanguageExtensions.rst
===================================================================
--- docs/LanguageExtensions.rst
+++ docs/LanguageExtensions.rst
@@ -1916,8 +1916,9 @@
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 Annotating a pointer with address space #256 causes it to be code generated
-relative to the X86 GS segment register, and address space #257 causes it to be
-relative to the X86 FS segment.  Note that this is a very very low-level
+relative to the X86 GS segment register, address space #257 causes it to be
+relative to the X86 FS segment, and address space #258 causes it to be
+relative to the X86 SS segment.  Note that this is a very very low-level
 feature that should only be used if you know what you're doing (for example in
 an OS kernel).