diff --git a/go.mod b/go.mod
index 453b51ed285936b6187ea630592e2b97f8026efb..68dcf48d930dc897197879841af25defdaf212c3 100644
--- a/go.mod
+++ b/go.mod
@@ -7,5 +7,5 @@ require (
 	github.com/jhillyerd/enmime v1.0.1
 	github.com/oschwald/geoip2-golang v1.9.0
 	github.com/prometheus/client_golang v1.11.0
-	golang.org/x/sync v0.4.0
+	golang.org/x/sync v0.5.0
 )
diff --git a/go.sum b/go.sum
index 5c631a1b50fc083b3da1d83fc4a0e853741eeb41..07af3db4bde98958e80b5957b13a7f814455278d 100644
--- a/go.sum
+++ b/go.sum
@@ -202,6 +202,8 @@ golang.org/x/sync v0.3.0 h1:ftCYgMx6zT/asHUrPw8BLLscYtGznsLAnjq5RH9P66E=
 golang.org/x/sync v0.3.0/go.mod h1:FU7BRWz2tNW+3quACPkgCx/L+uEAv1htQ0V83Z9Rj+Y=
 golang.org/x/sync v0.4.0 h1:zxkM55ReGkDlKSM+Fu41A+zmbZuaPVbGMzvvdUPznYQ=
 golang.org/x/sync v0.4.0/go.mod h1:FU7BRWz2tNW+3quACPkgCx/L+uEAv1htQ0V83Z9Rj+Y=
+golang.org/x/sync v0.5.0 h1:60k92dhOjHxJkrqnwsfl8KuaHbn/5dl0lUPUklKo3qE=
+golang.org/x/sync v0.5.0/go.mod h1:Czt+wKu1gCyEFDUtn0jG5QVvpJ6rzVqr5aXyt9drQfk=
 golang.org/x/sys v0.0.0-20180905080454-ebe1bf3edb33/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20181116152217-5ac8a444bdc5/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=