diff --git a/doc/src/base/math.md b/doc/src/base/math.md
index 62368424629c6..1b6b415b1d616 100644
--- a/doc/src/base/math.md
+++ b/doc/src/base/math.md
@@ -70,6 +70,7 @@ Base.Math.tand
 Base.Math.sincosd
 Base.Math.sinpi
 Base.Math.cospi
+Base.Math.tanpi
 Base.Math.sincospi
 Base.sinh(::Number)
 Base.cosh(::Number)