diff --git a/awc/CHANGES.md b/awc/CHANGES.md
index 507c8a080..46939a7ca 100644
--- a/awc/CHANGES.md
+++ b/awc/CHANGES.md
@@ -3,6 +3,7 @@
 ## Unreleased
 
 - Minimum supported Rust version (MSRV) is now 1.72.
+- Fix warning on 1.78 due to unused TlsConnectorService struct
 
 ## 3.4.0
 
diff --git a/awc/src/client/connector.rs b/awc/src/client/connector.rs
index 94629b955..b66e13ec7 100644
--- a/awc/src/client/connector.rs
+++ b/awc/src/client/connector.rs
@@ -649,6 +649,14 @@ where
 
 /// service for establish tcp connection and do client tls handshake.
 /// operation is canceled when timeout limit reached.
+#[cfg(any(
+    feature = "dangerous-h2c",
+    feature = "openssl",
+    feature = "rustls-0_20",
+    feature = "rustls-0_21",
+    feature = "rustls-0_22-webpki-roots",
+    feature = "rustls-0_22-native-roots",
+))]
 struct TlsConnectorService<Tcp, Tls> {
     /// TCP connection is canceled on `TcpConnectorInnerService`'s timeout setting.
     tcp_service: Tcp,
@@ -659,6 +667,14 @@ struct TlsConnectorService<Tcp, Tls> {
     timeout: Duration,
 }
 
+#[cfg(any(
+    feature = "dangerous-h2c",
+    feature = "openssl",
+    feature = "rustls-0_20",
+    feature = "rustls-0_21",
+    feature = "rustls-0_22-webpki-roots",
+    feature = "rustls-0_22-native-roots",
+))]
 impl<Tcp, Tls, IO> Service<Connect> for TlsConnectorService<Tcp, Tls>
 where
     Tcp: