diff --git a/examples/basic.rs b/examples/basic.rs
index 9a2da22..213838d 100644
--- a/examples/basic.rs
+++ b/examples/basic.rs
@@ -53,11 +53,10 @@ fn main() {
 				server_name.map_or_else(|| panic!("NO HOST"), str::to_string)
 			},
 			remote_port: "443".to_string(),
-			tls_config:
-				TLSConfig::FILE {
-					certificate_path: "/dev/shm/exp/certs/prime256v1/apple.com.crt".to_string(),
-					private_key_path: "/dev/shm/exp/certs/prime256v1/apple.com.key".to_string(),
-				},
+			tls_config: TLSConfig::FILE {
+				certificate_path: "/dev/shm/exp/certs/prime256v1/apple.com.crt".to_string(),
+				private_key_path: "/dev/shm/exp/certs/prime256v1/apple.com.key".to_string(),
+			},
 		},
 	);
 
diff --git a/src/lib.rs b/src/lib.rs
index b30a64e..394d256 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -146,6 +146,12 @@ pub enum TLSConfig {
 		certificate: Vec<u8>,
 		private_key: Vec<u8>,
 	},
+	CALLBACK {
+		servername_callback: fn(
+			&mut openssl::ssl::SslRef,
+			&mut openssl::ssl::SslAlert,
+		) -> Result<(), openssl::ssl::SniError>,
+	},
 	NONE,
 }
 
diff --git a/src/relay.rs b/src/relay.rs
index c5be34c..0ee0d04 100644
--- a/src/relay.rs
+++ b/src/relay.rs
@@ -42,6 +42,7 @@ impl<H: HandlerCallbacks + std::marker::Sync + std::marker::Send + Clone + 'stat
 							let r_port = rport.clone();
 
 							let this_conn_id = conn_id;
+
 							thread::spawn(move || {
 								match acceptor.accept(stream) {
 									Ok(stream) => {
@@ -50,7 +51,7 @@ impl<H: HandlerCallbacks + std::marker::Sync + std::marker::Send + Clone + 'stat
 											.servername(openssl::ssl::NameType::HOST_NAME);
 										handler_clone.cb.set_server_name(server_name);
 										let remote_host = (r_host)(server_name);
-										
+
 										// FULL DUPLEX OBJECT CREATION HERE
 										match FullDuplexTcp::new(
 											DataStreamType::TLS(stream),
@@ -154,6 +155,11 @@ impl<H: HandlerCallbacks + std::marker::Sync + std::marker::Send + Clone + 'stat
 					.unwrap();
 				acceptor.set_private_key(private_key.as_ref()).unwrap();
 			}
+			TLSConfig::CALLBACK {
+				servername_callback,
+			} => {
+				acceptor.set_servername_callback(*servername_callback);
+			}
 			TLSConfig::NONE => {
 				panic!(
 					"[SSLRelay Error] Specified NONE for TLSConfig and downstream_data_type as \