diff --git a/Cargo.toml b/Cargo.toml
index 290fe57..61d0bc1 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -96,10 +96,10 @@ native-tls-crate = { version = "0.2", optional = true, package = "native-tls" }
 tokio-tls = { version = "0.3.0", optional = true }
 
 # rustls-tls
-hyper-rustls = { version = "0.19", optional = true }
-rustls = { version = "0.16", features = ["dangerous_configuration"], optional = true }
-tokio-rustls = { version = "0.12", optional = true }
-webpki-roots = { version = "0.17", optional = true }
+hyper-rustls = { version = "0.20", optional = true }
+rustls = { version = "0.17", features = ["dangerous_configuration"], optional = true }
+tokio-rustls = { version = "0.13", optional = true }
+webpki-roots = { version = "0.18", optional = true }
 
 ## cookies
 cookie_crate = { version = "0.12", package = "cookie", optional = true }
diff --git a/src/tls.rs b/src/tls.rs
index 90ee494..2e16344 100644
--- a/src/tls.rs
+++ b/src/tls.rs
@@ -245,7 +245,7 @@ impl Identity {
     pub(crate) fn add_to_rustls(self, tls: &mut rustls::ClientConfig) -> crate::Result<()> {
         match self.inner {
             ClientCert::Pem { key, certs } => {
-                tls.set_single_client_cert(certs, key);
+                tls.set_single_client_cert(certs, key).map_err(|e| crate::error::builder(e))?;
                 Ok(())
             }
             #[cfg(feature = "native-tls")]