diff --git a/actix-http/CHANGES.md b/actix-http/CHANGES.md
index 0c5da36d7..9edd7b6f0 100644
--- a/actix-http/CHANGES.md
+++ b/actix-http/CHANGES.md
@@ -2,6 +2,10 @@
 
 ## Unreleased
 
+- Encode the HTTP/1 `Connection: Upgrade` header in Camel-Case when camel-case header formatting is enabled.[#3953]
+
+[#3953]: https://github.com/actix/actix-web/pull/3953
+
 ## 3.12.0
 
 - Minimum supported Rust version (MSRV) is now 1.88.
diff --git a/actix-http/src/h1/encoder.rs b/actix-http/src/h1/encoder.rs
index 81af7868b..1853843c3 100644
--- a/actix-http/src/h1/encoder.rs
+++ b/actix-http/src/h1/encoder.rs
@@ -111,7 +111,13 @@ pub(crate) trait MessageType: Sized {
 
         // Connection
         match conn_type {
-            ConnectionType::Upgrade => dst.put_slice(b"connection: upgrade\r\n"),
+            ConnectionType::Upgrade => {
+                if camel_case {
+                    dst.put_slice(b"Connection: Upgrade\r\n")
+                } else {
+                    dst.put_slice(b"connection: upgrade\r\n")
+                }
+            }
             ConnectionType::KeepAlive if version < Version::HTTP_11 => {
                 if camel_case {
                     dst.put_slice(b"Connection: keep-alive\r\n")
@@ -580,6 +586,16 @@ mod tests {
         assert!(data.contains("Date: date\r\n"));
         assert!(data.contains("Upgrade-Insecure-Requests: 1\r\n"));
 
+        let _ = head.encode_headers(
+            &mut bytes,
+            Version::HTTP_11,
+            BodySize::None,
+            ConnectionType::Upgrade,
+            &ServiceConfig::default(),
+        );
+        let data = String::from_utf8(Vec::from(bytes.split().freeze().as_ref())).unwrap();
+        assert!(data.contains("Connection: Upgrade\r\n"));
+
         let _ = head.encode_headers(
             &mut bytes,
             Version::HTTP_11,
diff --git a/actix-http/src/requests/head.rs b/actix-http/src/requests/head.rs
index 9ceb2a20c..ddc9dd98f 100644
--- a/actix-http/src/requests/head.rs
+++ b/actix-http/src/requests/head.rs
@@ -61,14 +61,15 @@ impl RequestHead {
         &mut self.headers
     }
 
-    /// Is to uppercase headers with Camel-Case.
-    /// Default is `false`
+    /// Returns whether headers should be sent in Camel-Case.
+    ///
+    /// Default is `false`.
     #[inline]
     pub fn camel_case_headers(&self) -> bool {
         self.flags.contains(Flags::CAMEL_CASE)
     }
 
-    /// Set `true` to send headers which are formatted as Camel-Case.
+    /// Sets whether to send headers formatted as Camel-Case.
     #[inline]
     pub fn set_camel_case_headers(&mut self, val: bool) {
         if val {
diff --git a/awc/CHANGES.md b/awc/CHANGES.md
index 49159b18d..38a9f8b09 100644
--- a/awc/CHANGES.md
+++ b/awc/CHANGES.md
@@ -2,6 +2,10 @@
 
 ## Unreleased
 
+- Add camel-case header controls to `WebsocketsRequest` via `camel_case_headers()` and `set_camel_case_headers()`. [#3953]
+
+[#3953]: https://github.com/actix/actix-web/pull/3953
+
 ## 3.8.2
 
 - Minimum supported Rust version (MSRV) is now 1.88.
diff --git a/awc/src/ws.rs b/awc/src/ws.rs
index c33531d41..de8ed2d14 100644
--- a/awc/src/ws.rs
+++ b/awc/src/ws.rs
@@ -245,6 +245,21 @@ impl WebsocketsRequest {
         self.header(AUTHORIZATION, format!("Bearer {}", token))
     }
 
+    /// Returns whether headers should be sent in Camel-Case.
+    ///
+    /// Default is `false`.
+    #[inline]
+    pub fn camel_case_headers(&self) -> bool {
+        self.head.camel_case_headers()
+    }
+
+    /// Sets whether to send headers formatted as Camel-Case.
+    #[inline]
+    pub fn set_camel_case_headers(mut self, val: bool) -> Self {
+        self.head.set_camel_case_headers(val);
+        self
+    }
+
     /// Complete request construction and connect to a WebSocket server.
     pub async fn connect(
         mut self,
@@ -529,6 +544,12 @@ mod tests {
         let _ = req.connect();
     }
 
+    #[actix_rt::test]
+    async fn camel_case_headers() {
+        let req = Client::new().ws("/").set_camel_case_headers(true);
+        assert!(req.camel_case_headers());
+    }
+
     #[actix_rt::test]
     async fn basics() {
         let req = Client::new()