--- bc/doc/bc.texi
+++ bc/doc/bc.texi
@@ -16,6 +16,7 @@
 @c end tex
 
 @ifinfo
+@dircategory Math
 @direntry
 * bc: (bc).                    An arbitrary precision calculator language.
 @end direntry
--- bc/doc/dc.texi
+++ bc/doc/dc.texi
@@ -18,6 +18,7 @@
 @syncodeindex pg fn
 @syncodeindex tp fn
 
+@dircategory Math
 @direntry
 * dc: (dc).                   Arbitrary precision RPN ``Desktop Calculator''.
 @end direntry