diff --git a/go.mod b/go.mod
index eed123b..e19ac72 100644
--- a/go.mod
+++ b/go.mod
@@ -2,7 +2,6 @@
 
 require (
 	github.com/VividCortex/ewma v1.1.1
-	github.com/mattn/go-isatty v0.0.4
 	golang.org/x/crypto v0.0.0-20190131182504-b8fe1690c613
-	golang.org/x/sys v0.0.0-20190203050204-7ae0202eb74c // indirect
+	golang.org/x/sys v0.0.0-20190204203706-41f3e6584952 // indirect
 )
diff --git a/go.sum b/go.sum
index 53b6e79..7b0502e 100644
--- a/go.sum
+++ b/go.sum
@@ -1,8 +1,6 @@
 github.com/VividCortex/ewma v1.1.1 h1:MnEK4VOv6n0RSY4vtRe3h11qjxL3+t0B8yOL8iMXdcM=
 github.com/VividCortex/ewma v1.1.1/go.mod h1:2Tkkvm3sRDVXaiyucHiACn4cqf7DpdyLvmxzcbUokwA=
-github.com/mattn/go-isatty v0.0.4 h1:bnP0vzxcAdeI1zdubAl5PjU6zsERjGZb7raWodagDYs=
-github.com/mattn/go-isatty v0.0.4/go.mod h1:M+lRXTBqGeGNdLjl/ufCoiOlB5xdOkqRJdNxMWT7Zi4=
 golang.org/x/crypto v0.0.0-20190131182504-b8fe1690c613 h1:MQ/ZZiDsUapFFiMS+vzwXkCTeEKaum+Do5rINYJDmxc=
 golang.org/x/crypto v0.0.0-20190131182504-b8fe1690c613/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=
-golang.org/x/sys v0.0.0-20190203050204-7ae0202eb74c h1:YeMXU0KQqExdpG959DFhAhfpY8myIsnfqj8lhNFRzzE=
-golang.org/x/sys v0.0.0-20190203050204-7ae0202eb74c/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/sys v0.0.0-20190204203706-41f3e6584952 h1:FDfvYgoVsA7TTZSbgiqjAbfPbK47CNHdWl3h/PJtii0=
+golang.org/x/sys v0.0.0-20190204203706-41f3e6584952/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=