diff --git a/src/math/acosh.go b/src/math/acosh.go
index cc8195ce328..41ca87123c2 100644
--- a/src/math/acosh.go
+++ b/src/math/acosh.go
@@ -42,10 +42,7 @@ package math
 func Acosh(x float64) float64
 
 func acosh(x float64) float64 {
-	const (
-		Ln2   = 6.93147180559945286227e-01 // 0x3FE62E42FEFA39EF
-		Large = 1 << 28                    // 2**28
-	)
+	const Large = 1 << 28 // 2**28
 	// first case is special case
 	switch {
 	case x < 1 || IsNaN(x):