diff --git a/tonic/src/transport/service/connector.rs b/tonic/src/transport/service/connector.rs
index c4d216b83..c1c99dfae 100644
--- a/tonic/src/transport/service/connector.rs
+++ b/tonic/src/transport/service/connector.rs
@@ -80,9 +80,17 @@ where
         #[cfg(feature = "tls-roots-common")]
         let tls = self.tls_or_default(uri.scheme_str(), uri.host());
 
+        let is_https = uri.scheme_str() == Some("https");
         let connect = self.inner.make_connection(uri);
 
         Box::pin(async move {
+            #[cfg(not(feature = "tls"))]
+            {
+                if is_https && tls.is_some() {
+                    return Err("connecting to HTTPS without TLS enabled".to_owned().into());
+                }
+            }
+
             let io = connect.await?;
 
             #[cfg(feature = "tls")]
@@ -90,6 +98,8 @@ where
                 if let Some(tls) = tls {
                     let conn = tls.connect(io).await?;
                     return Ok(BoxedIo::new(conn));
+                } else if is_https {
+                    return Err("connecting to HTTPS without TLS enabled".to_owned().into());
                 }
             }