diff --git a/worker-sys/src/ext.rs b/worker-sys/src/ext.rs
index d75484231..2e68d5f37 100644
--- a/worker-sys/src/ext.rs
+++ b/worker-sys/src/ext.rs
@@ -1,5 +1,6 @@
 mod abort_controller;
 mod cache_storage;
+mod headers;
 mod request;
 mod response;
 mod response_init;
@@ -7,6 +8,7 @@ mod websocket;
 
 pub use abort_controller::*;
 pub use cache_storage::*;
+pub use headers::HeadersExt;
 pub use request::*;
 pub use response::*;
 pub use response_init::*;
diff --git a/worker-sys/src/ext/headers.rs b/worker-sys/src/ext/headers.rs
new file mode 100644
index 000000000..c4bc55ab7
--- /dev/null
+++ b/worker-sys/src/ext/headers.rs
@@ -0,0 +1,24 @@
+use wasm_bindgen::prelude::*;
+
+mod glue {
+    use super::*;
+
+    #[wasm_bindgen]
+    extern "C" {
+        #[wasm_bindgen(extends = js_sys::Object)]
+        pub type Headers;
+
+        #[wasm_bindgen(method, js_name = getAll)]
+        pub fn get_all(this: &Headers, name: &str) -> js_sys::Array;
+    }
+}
+
+pub trait HeadersExt {
+    fn get_all(&self, name: &str) -> js_sys::Array;
+}
+
+impl HeadersExt for web_sys::Headers {
+    fn get_all(&self, name: &str) -> js_sys::Array {
+        self.unchecked_ref::<glue::Headers>().get_all(name)
+    }
+}
diff --git a/worker/src/headers.rs b/worker/src/headers.rs
index e2c2bbdbf..7cd977327 100644
--- a/worker/src/headers.rs
+++ b/worker/src/headers.rs
@@ -9,6 +9,7 @@ use std::{
 use http::{header::HeaderName, HeaderMap, HeaderValue};
 use js_sys::Array;
 use wasm_bindgen::JsValue;
+use worker_sys::ext::HeadersExt;
 
 /// A [Headers](https://developer.mozilla.org/en-US/docs/Web/API/Headers) representation used in
 /// Request and Response objects.
@@ -90,6 +91,18 @@ impl Headers {
             // The values iterator.next() will always return a proper value containing a string
             .map(|a| a.unwrap().as_string().unwrap())
     }
+
+    /// Returns all the values of a header within a `Headers` object with a given name.
+    pub fn get_all(&self, name: &str) -> Result<Vec<String>> {
+        let array = self.0.get_all(name);
+        array
+            .iter()
+            .map(|v| {
+                v.as_string()
+                    .ok_or_else(|| Error::JsError("Invalid header value".into()))
+            })
+            .collect()
+    }
 }
 
 impl Default for Headers {