diff --git a/doc/src/base/math.md b/doc/src/base/math.md
index c1b18c0b66d86..7091aa6f1aa87 100644
--- a/doc/src/base/math.md
+++ b/doc/src/base/math.md
@@ -74,6 +74,7 @@ Base.Math.tand
 Base.Math.sincosd
 Base.Math.sinpi
 Base.Math.cospi
+Base.Math.tanpi
 Base.Math.sincospi
 Base.sinh(::Number)
 Base.cosh(::Number)