diff --git a/src/api/request.rs b/src/api/request.rs
index 505c6a14..3f90b093 100644
--- a/src/api/request.rs
+++ b/src/api/request.rs
@@ -20,7 +20,11 @@ impl Request {
             let header_name = Ident::from(header_name_string.as_ref());
 
             header_tokens.append_all(quote! {
-                headers.append(::http::header::#header_name, request.#field_name);
+                headers.append(
+                    ::http::header::#header_name,
+                    ::http::header::HeaderValue::from_str(request.#field_name.as_ref())
+                        .expect("failed to convert value into HeaderValue"),
+                );
             });
 
             header_tokens
diff --git a/src/api/response.rs b/src/api/response.rs
index 3f08327e..12ac6c72 100644
--- a/src/api/response.rs
+++ b/src/api/response.rs
@@ -41,7 +41,10 @@ impl Response {
 
                     tokens.append_all(quote_spanned! {span=>
                         #field_name: headers.remove(::http::header::#header_name)
-                            .expect("missing expected request header"),
+                            .expect("response missing expected header")
+                            .to_str()
+                            .expect("failed to convert HeaderValue to str")
+                            .to_owned(),
                     });
                 }
                 ResponseField::NewtypeBody(ref field) => {
diff --git a/src/lib.rs b/src/lib.rs
index bff2b4aa..6306380d 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -80,8 +80,8 @@ mod api;
 ///
 /// *   `#[ruma_api(header = "HEADER_NAME")]`: Fields with this attribute will be treated as HTTP
 ///     headers on the request.
-///     The value must implement `http::HttpTryFrom for http::header::HeaderValue`.
-///     Generally this is a string.
+///     The value must implement `AsRef<str>`.
+///     Generally this is a `String`.
 ///     The attribute value shown above as `HEADER_NAME` must be a header name constant from
 ///     `http::header`, e.g. `CONTENT_TYPE`.
 /// *   `#[ruma_api(path)]`: Fields with this attribute will be inserted into the matching path
@@ -101,8 +101,8 @@ mod api;
 ///
 /// *   `#[ruma_api(header = "HEADER_NAME")]`: Fields with this attribute will be treated as HTTP
 ///     headers on the response.
-///     The value must implement `http::HttpTryFrom for http::header::HeaderValue`.
-///     Generally this is a string.
+///     The value must implement `AsRef<str>`.
+///     Generally this is a `String`.
 ///     The attribute value shown above as `HEADER_NAME` must be a header name constant from
 ///     `http::header`, e.g. `CONTENT_TYPE`.
 ///