diff --git a/doc/ext/math.rst b/doc/ext/math.rst
index fe7b85c83..0fb3a17cf 100644
--- a/doc/ext/math.rst
+++ b/doc/ext/math.rst
@@ -46,10 +46,10 @@ or use Python raw strings (``r"raw"``).
 
 .. confval:: math_numfig
 
-   If ``True``, displayed math equations are numbered across pages using numfig.
-   The :confval:`numfig` config value must be enabled and
-   :confval:`numfig_secnum_depth` is respected.  The ``:eq:`` role must be used
-   to refererence these equation numbers, not the ``:numref:`` role.
+   If ``True``, displayed math equations are numbered across pages in html and
+   related (epub, ...) output.  The :confval:`numfig` config value must be
+   enabled and :confval:`numfig_secnum_depth` is respected.  The ``:eq:`` role
+   must be used to reference equation numbers, not the ``:numref:`` role.
    Default is ``False``.
 
 :mod:`.mathbase` defines these new markup elements: