diff --git a/man3/ctanh.3 b/man3/ctanh.3
index dc1f514d2..eaf440c38 100644
--- a/man3/ctanh.3
+++ b/man3/ctanh.3
@@ -18,6 +18,9 @@ ctanh, ctanhf, ctanhl \- complex hyperbolic tangent
 .sp
 Link with \fI\-lm\fP.
 .SH DESCRIPTION
+These functions calculate the complex hyperbolic tangent of
+.IR z .
+
 The complex hyperbolic tangent function is defined
 mathematically as:
 .nf