diff --git a/go.mod b/go.mod
index cb2fa35..1d26b73 100644
--- a/go.mod
+++ b/go.mod
@@ -2,4 +2,4 @@ module github.com/tklauser/numcpus
 
 go 1.13
 
-require golang.org/x/sys v0.3.0
+require golang.org/x/sys v0.4.0
diff --git a/go.sum b/go.sum
index 2738fca..c2a6782 100644
--- a/go.sum
+++ b/go.sum
@@ -1,2 +1,2 @@
-golang.org/x/sys v0.3.0 h1:w8ZOecv6NaNa/zC8944JTU3vz4u6Lagfk4RPQxv92NQ=
-golang.org/x/sys v0.3.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.4.0 h1:Zr2JFtRQNX3BCZ8YtxRE9hNJYC8J6I1MVbMg6owUp18=
+golang.org/x/sys v0.4.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=