diff --git a/Cargo.toml b/Cargo.toml
index 204cbd1df..642a97d32 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -71,7 +71,7 @@ socks = ["tokio-socks"]
 # Don't rely on these whatsoever. They may disappear at anytime.
 
 # Enables common types used for TLS. Useless on its own.
-__tls = ["dep:rustls-pemfile"]
+__tls = ["dep:rustls-pemfile", "tokio/io-util"]
 
 # Enables common rustls code.
 # Equivalent to rustls-tls-manual-roots but shorter :)