diff --git a/gas/doc/a29k.m4 b/gas/doc/a29k.m4
index dbe013406d..48ae61a1c7 100644
--- a/gas/doc/a29k.m4
+++ b/gas/doc/a29k.m4
@@ -1,3 +1,4 @@
 _divert__(-1)
 _define__(<_AMD29K__>,<1>)
+_define__(<_MACH_DEP__>,<AMD29K Dependent>
 _divert__<>
\ No newline at end of file