diff --git a/Cargo.toml b/Cargo.toml
index eaa9638..57ce896 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -41,7 +41,7 @@ winapi = { version="0.3.9", features=["winsock2"], optional = true }
 default = ["proxy", "rustls"]
 proxy = ["byteorder", "winapi", "libc"]
 rustls = ["webpki-roots", "dep:rustls", "rustls/default"]
-rustls-ring = ["webpki-roots", "dep:rustls", "rustls/ring", "rustls/logging", "rustls/std", "rustls/tls12"]
+rustls-ring = ["webpki-roots", "dep:rustls", "rustls?/ring", "rustls?/logging", "rustls?/std", "rustls?/tls12"]
 openssl = ["dep:openssl"]
 
 # Old feature names