diff --git a/ginsh/ginsh.1.in b/ginsh/ginsh.1.in
index 80b66122..61741683 100644
--- a/ginsh/ginsh.1.in
+++ b/ginsh/ginsh.1.in
@@ -368,6 +368,9 @@ detail here. Please refer to the GiNaC documentation.
 .BI series( expression ", " relation-or-symbol ", " order )
 \- series expansion
 .br
+.BI series_to_poly( series )
+\- convert a series into a polynomial by dropping the Order() term
+.br
 .BI sprem( expression ", " expression ", " symbol )
 \- sparse pseudo-remainder of polynomials
 .br