diff --git a/rustls-mio/Cargo.toml b/rustls-mio/Cargo.toml
index 24d4bc53..02859b7a 100644
--- a/rustls-mio/Cargo.toml
+++ b/rustls-mio/Cargo.toml
@@ -23,7 +23,7 @@ webpki = "0.21.0"
 ct-logs = "0.6"
 docopt = "~1.1"
 env_logger = "0.7.1"
-mio = "0.6.14"
+mio = { version = "0.7", features = ["os-poll", "tcp"] }
 regex = "1.0"
 serde = "1.0"
 serde_derive = "1.0"