diff --git a/ruma-api-macros/src/api/request/incoming.rs b/ruma-api-macros/src/api/request/incoming.rs
index cfb8828a..e68a599b 100644
--- a/ruma-api-macros/src/api/request/incoming.rs
+++ b/ruma-api-macros/src/api/request/incoming.rs
@@ -10,7 +10,6 @@ impl Request {
         error_ty: &TokenStream,
         ruma_api: &TokenStream,
     ) -> TokenStream {
-        let bytes = quote! { #ruma_api::exports::bytes };
         let http = quote! { #ruma_api::exports::http };
         let percent_encoding = quote! { #ruma_api::exports::percent_encoding };
         let ruma_serde = quote! { #ruma_api::exports::ruma_serde };
@@ -159,15 +158,17 @@ impl Request {
                     RequestBody #body_lifetimes
                     as #ruma_serde::Outgoing
                 >::Incoming = {
-                    let body = request.into_body();
-                    if #bytes::Buf::has_remaining(&body) {
-                        #serde_json::from_reader(#bytes::Buf::reader(body))?
-                    } else {
+                    let body = ::std::convert::AsRef::<[::std::primitive::u8]>::as_ref(
+                        request.body(),
+                    );
+
+                    #serde_json::from_slice(match body {
                         // If the request body is completely empty, pretend it is an empty JSON
                         // object instead. This allows requests with only optional body parameters
                         // to be deserialized in that case.
-                        #serde_json::from_str("{}")?
-                    }
+                        [] => b"{}",
+                        b => b,
+                    })?
                 };
             }
         } else {
@@ -184,13 +185,8 @@ impl Request {
         } else if let Some(field) = self.newtype_raw_body_field() {
             let field_name = field.ident.as_ref().expect("expected field to have an identifier");
             let parse = quote! {
-                let #field_name = {
-                    let mut reader = #bytes::Buf::reader(request.into_body());
-                    let mut vec = ::std::vec::Vec::new();
-                    ::std::io::Read::read_to_end(&mut reader, &mut vec)
-                        .expect("reading from a bytes::Buf never fails");
-                    vec
-                };
+                let #field_name =
+                    ::std::convert::AsRef::<[u8]>::as_ref(request.body()).to_vec();
             };
 
             (parse, quote! { #field_name, })
diff --git a/ruma-api-macros/src/api/response/incoming.rs b/ruma-api-macros/src/api/response/incoming.rs
index daf98857..4353cc4b 100644
--- a/ruma-api-macros/src/api/response/incoming.rs
+++ b/ruma-api-macros/src/api/response/incoming.rs
@@ -5,7 +5,6 @@ use super::{Response, ResponseField};
 
 impl Response {
     pub fn expand_incoming(&self, error_ty: &TokenStream, ruma_api: &TokenStream) -> TokenStream {
-        let bytes = quote! { #ruma_api::exports::bytes };
         let http = quote! { #ruma_api::exports::http };
         let ruma_serde = quote! { #ruma_api::exports::ruma_serde };
         let serde_json = quote! { #ruma_api::exports::serde_json };
@@ -25,15 +24,17 @@ impl Response {
                         ResponseBody
                         as #ruma_serde::Outgoing
                     >::Incoming = {
-                        let body = response.into_body();
-                        if #bytes::Buf::has_remaining(&body) {
-                            #serde_json::from_reader(#bytes::Buf::reader(body))?
-                        } else {
+                        let body = ::std::convert::AsRef::<[::std::primitive::u8]>::as_ref(
+                            response.body(),
+                        );
+
+                        #serde_json::from_slice(match body {
                             // If the response body is completely empty, pretend it is an empty
                             // JSON object instead. This allows responses with only optional body
                             // parameters to be deserialized in that case.
-                            #serde_json::from_str("{}")?
-                        }
+                            [] => b"{}",
+                            b => b,
+                        })?
                     };
                 }
             } else {
@@ -93,11 +94,10 @@ impl Response {
                     ResponseField::NewtypeRawBody(_) => {
                         new_type_raw_body = Some(quote! {
                             #field_name: {
-                                let mut reader = #bytes::Buf::reader(response.into_body());
-                                let mut vec = ::std::vec::Vec::new();
-                                ::std::io::Read::read_to_end(&mut reader, &mut vec)
-                                    .expect("reading from a bytes::Buf never fails");
-                                vec
+                                ::std::convert::AsRef::<[::std::primitive::u8]>::as_ref(
+                                    response.body(),
+                                )
+                                .to_vec()
                             }
                         });
                         // skip adding to the vec
@@ -120,7 +120,7 @@ impl Response {
             impl #ruma_api::IncomingResponse for Response {
                 type EndpointError = #error_ty;
 
-                fn try_from_http_response<T: #bytes::Buf>(
+                fn try_from_http_response<T: ::std::convert::AsRef<[::std::primitive::u8]>>(
                     response: #http::Response<T>,
                 ) -> ::std::result::Result<
                     Self,
@@ -130,15 +130,17 @@ impl Response {
                         #extract_response_headers
                         #typed_response_body_decl
 
-                        Ok(Self {
+                        ::std::result::Result::Ok(Self {
                             #response_init_fields
                         })
                     } else {
                         match <#error_ty as #ruma_api::EndpointError>::try_from_http_response(
                             response
                         ) {
-                            Ok(err) => Err(#ruma_api::error::ServerError::Known(err).into()),
-                            Err(response_err) => {
+                            ::std::result::Result::Ok(err) => {
+                                Err(#ruma_api::error::ServerError::Known(err).into())
+                            }
+                            ::std::result::Result::Err(response_err) => {
                                 Err(#ruma_api::error::ServerError::Unknown(response_err).into())
                             }
                         }
diff --git a/ruma-api/Cargo.toml b/ruma-api/Cargo.toml
index 39c4689c..4e539f10 100644
--- a/ruma-api/Cargo.toml
+++ b/ruma-api/Cargo.toml
@@ -19,7 +19,6 @@ all-features = true
 rustdoc-args = ["--cfg", "docsrs"]
 
 [dependencies]
-bytes = "1.0.1"
 http = "0.2.2"
 percent-encoding = "2.1.0"
 ruma-api-macros = { version = "=0.17.0-alpha.2", path = "../ruma-api-macros" }
diff --git a/ruma-api/src/error.rs b/ruma-api/src/error.rs
index 8b8cc13e..154c3d42 100644
--- a/ruma-api/src/error.rs
+++ b/ruma-api/src/error.rs
@@ -4,7 +4,6 @@
 
 use std::{error::Error as StdError, fmt};
 
-use bytes::Buf;
 use thiserror::Error;
 
 use crate::{EndpointError, OutgoingResponse};
@@ -21,7 +20,7 @@ impl OutgoingResponse for Void {
 }
 
 impl EndpointError for Void {
-    fn try_from_http_response<T: Buf>(
+    fn try_from_http_response<T: AsRef<[u8]>>(
         _response: http::Response<T>,
     ) -> Result<Self, ResponseDeserializationError> {
         Err(ResponseDeserializationError::none())
diff --git a/ruma-api/src/lib.rs b/ruma-api/src/lib.rs
index 02e3890e..3baddcdf 100644
--- a/ruma-api/src/lib.rs
+++ b/ruma-api/src/lib.rs
@@ -22,7 +22,6 @@ compile_error!("ruma_api's Cargo features only exist as a workaround are not mea
 
 use std::{convert::TryInto as _, error::Error as StdError};
 
-use bytes::Buf;
 use http::Method;
 use ruma_identifiers::UserId;
 
@@ -204,7 +203,6 @@ pub mod error;
 /// It is not considered part of ruma-api's public API.
 #[doc(hidden)]
 pub mod exports {
-    pub use bytes;
     pub use http;
     pub use percent_encoding;
     pub use ruma_serde;
@@ -246,7 +244,7 @@ pub trait IncomingResponse: Sized {
     type EndpointError: EndpointError;
 
     /// Tries to convert the given `http::Response` into this response type.
-    fn try_from_http_response<T: Buf>(
+    fn try_from_http_response<T: AsRef<[u8]>>(
         response: http::Response<T>,
     ) -> Result<Self, FromHttpResponseError<Self::EndpointError>>;
 }
@@ -301,7 +299,9 @@ pub trait IncomingRequest: Sized {
     const METADATA: Metadata;
 
     /// Tries to turn the given `http::Request` into this request type.
-    fn try_from_http_request<T: Buf>(req: http::Request<T>) -> Result<Self, FromHttpRequestError>;
+    fn try_from_http_request<T: AsRef<[u8]>>(
+        req: http::Request<T>,
+    ) -> Result<Self, FromHttpRequestError>;
 }
 
 /// A request type for a Matrix API endpoint, used for sending responses.
@@ -319,7 +319,7 @@ pub trait EndpointError: OutgoingResponse + StdError + Sized + 'static {
     ///
     /// This will always return `Err` variant when no `error` field is defined in
     /// the `ruma_api` macro.
-    fn try_from_http_response<T: Buf>(
+    fn try_from_http_response<T: AsRef<[u8]>>(
         response: http::Response<T>,
     ) -> Result<Self, error::ResponseDeserializationError>;
 }
diff --git a/ruma-api/tests/conversions.rs b/ruma-api/tests/conversions.rs
index 144aaad3..3d9a9e4f 100644
--- a/ruma-api/tests/conversions.rs
+++ b/ruma-api/tests/conversions.rs
@@ -48,7 +48,7 @@ fn request_serde() {
     };
 
     let http_req = req.clone().try_into_http_request("https://homeserver.tld", None).unwrap();
-    let req2 = Request::try_from_http_request(http_req.map(std::io::Cursor::new)).unwrap();
+    let req2 = Request::try_from_http_request(http_req).unwrap();
 
     assert_eq!(req.hello, req2.hello);
     assert_eq!(req.world, req2.world);
diff --git a/ruma-api/tests/manual_endpoint_impl.rs b/ruma-api/tests/manual_endpoint_impl.rs
index d28b9e63..0e25dca2 100644
--- a/ruma-api/tests/manual_endpoint_impl.rs
+++ b/ruma-api/tests/manual_endpoint_impl.rs
@@ -2,7 +2,6 @@
 
 use std::convert::TryFrom;
 
-use bytes::Buf;
 use http::{header::CONTENT_TYPE, method::Method};
 use ruma_api::{
     error::{FromHttpRequestError, FromHttpResponseError, IntoHttpError, ServerError, Void},
@@ -67,7 +66,7 @@ impl IncomingRequest for Request {
 
     const METADATA: Metadata = METADATA;
 
-    fn try_from_http_request<T: Buf>(
+    fn try_from_http_request<T: AsRef<[u8]>>(
         request: http::Request<T>,
     ) -> Result<Self, FromHttpRequestError> {
         let path_segments: Vec<&str> = request.uri().path()[1..].split('/').collect();
@@ -78,7 +77,7 @@ impl IncomingRequest for Request {
             TryFrom::try_from(&*decoded)?
         };
 
-        let request_body: RequestBody = serde_json::from_reader(request.into_body().reader())?;
+        let request_body: RequestBody = serde_json::from_slice(request.body().as_ref())?;
 
         Ok(Request { room_id: request_body.room_id, room_alias })
     }
@@ -100,7 +99,7 @@ impl Outgoing for Response {
 impl IncomingResponse for Response {
     type EndpointError = Void;
 
-    fn try_from_http_response<T: Buf>(
+    fn try_from_http_response<T: AsRef<[u8]>>(
         http_response: http::Response<T>,
     ) -> Result<Self, FromHttpResponseError<Void>> {
         if http_response.status().as_u16() < 400 {
diff --git a/ruma-api/tests/ui/05-request-only.rs b/ruma-api/tests/ui/05-request-only.rs
index 49af1b29..9e01fc95 100644
--- a/ruma-api/tests/ui/05-request-only.rs
+++ b/ruma-api/tests/ui/05-request-only.rs
@@ -1,4 +1,3 @@
-use bytes::Buf;
 use ruma_api::{
     error::{FromHttpResponseError, IntoHttpError, Void},
     ruma_api, IncomingResponse, OutgoingResponse,
@@ -28,7 +27,7 @@ pub struct Response;
 impl IncomingResponse for Response {
     type EndpointError = Void;
 
-    fn try_from_http_response<T: Buf>(
+    fn try_from_http_response<T: AsRef<[u8]>>(
         _: http::Response<T>,
     ) -> Result<Self, FromHttpResponseError<Void>> {
         todo!()
diff --git a/ruma-client-api/Cargo.toml b/ruma-client-api/Cargo.toml
index 7b4b4408..0bb3f149 100644
--- a/ruma-client-api/Cargo.toml
+++ b/ruma-client-api/Cargo.toml
@@ -17,7 +17,6 @@ edition = "2018"
 
 [dependencies]
 assign = "1.1.1"
-bytes = "1.0.1"
 http = "0.2.2"
 js_int = { version = "0.2.0", features = ["serde"] }
 maplit = "1.0.2"
diff --git a/ruma-client-api/src/error.rs b/ruma-client-api/src/error.rs
index b1b8996f..f0e599e1 100644
--- a/ruma-client-api/src/error.rs
+++ b/ruma-client-api/src/error.rs
@@ -2,14 +2,13 @@
 
 use std::{collections::BTreeMap, fmt, time::Duration};
 
-use bytes::Buf;
 use ruma_api::{
     error::{IntoHttpError, ResponseDeserializationError},
     EndpointError, OutgoingResponse,
 };
 use ruma_identifiers::RoomVersionId;
 use serde::{Deserialize, Serialize};
-use serde_json::{from_reader as from_json_reader, to_vec as to_json_vec, Value as JsonValue};
+use serde_json::{from_slice as from_json_slice, to_vec as to_json_vec, Value as JsonValue};
 
 /// Deserialize and Serialize implementations for ErrorKind.
 /// Separate module because it's a lot of code.
@@ -206,11 +205,11 @@ pub struct Error {
 }
 
 impl EndpointError for Error {
-    fn try_from_http_response<T: Buf>(
+    fn try_from_http_response<T: AsRef<[u8]>>(
         response: http::Response<T>,
     ) -> Result<Self, ResponseDeserializationError> {
         let status = response.status();
-        let error_body: ErrorBody = from_json_reader(response.into_body().reader())?;
+        let error_body: ErrorBody = from_json_slice(response.body().as_ref())?;
         Ok(error_body.into_error(status))
     }
 }
diff --git a/ruma-client-api/src/r0/message/send_message_event.rs b/ruma-client-api/src/r0/message/send_message_event.rs
index 832143db..aba490af 100644
--- a/ruma-client-api/src/r0/message/send_message_event.rs
+++ b/ruma-client-api/src/r0/message/send_message_event.rs
@@ -104,7 +104,7 @@ impl ruma_api::IncomingRequest for IncomingRequest {
 
     const METADATA: ruma_api::Metadata = METADATA;
 
-    fn try_from_http_request<T: bytes::Buf>(
+    fn try_from_http_request<T: AsRef<[u8]>>(
         request: http::Request<T>,
     ) -> Result<Self, ruma_api::error::FromHttpRequestError> {
         use std::convert::TryFrom;
@@ -129,7 +129,7 @@ impl ruma_api::IncomingRequest for IncomingRequest {
         let content = {
             let event_type =
                 percent_encoding::percent_decode(path_segments[6].as_bytes()).decode_utf8()?;
-            let body: Box<RawJsonValue> = serde_json::from_reader(body.reader())?;
+            let body: Box<RawJsonValue> = serde_json::from_slice(body.as_ref())?;
 
             AnyMessageEventContent::from_parts(&event_type, body)?
         };
diff --git a/ruma-client-api/src/r0/profile/set_avatar_url.rs b/ruma-client-api/src/r0/profile/set_avatar_url.rs
index 0013e433..e877bead 100644
--- a/ruma-client-api/src/r0/profile/set_avatar_url.rs
+++ b/ruma-client-api/src/r0/profile/set_avatar_url.rs
@@ -77,9 +77,8 @@ mod tests {
                 http::Request::builder()
                     .method("PUT")
                     .uri("https://bar.org/_matrix/client/r0/profile/@foo:bar.org/avatar_url")
-                    .body(std::io::Cursor::new(
-                        serde_json::to_vec(&serde_json::json!({ "avatar_url": "" })).unwrap(),
-                    )).unwrap(),
+                    .body(serde_json::to_vec(&serde_json::json!({ "avatar_url": "" })).unwrap())
+                    .unwrap(),
             ).unwrap(),
             IncomingRequest { user_id, avatar_url: None } if user_id == "@foo:bar.org"
         );
diff --git a/ruma-client-api/src/r0/state/get_state_events_for_key.rs b/ruma-client-api/src/r0/state/get_state_events_for_key.rs
index 6c631755..b3b2d2f1 100644
--- a/ruma-client-api/src/r0/state/get_state_events_for_key.rs
+++ b/ruma-client-api/src/r0/state/get_state_events_for_key.rs
@@ -108,7 +108,7 @@ impl ruma_api::IncomingRequest for IncomingRequest {
 
     const METADATA: ruma_api::Metadata = METADATA;
 
-    fn try_from_http_request<T: bytes::Buf>(
+    fn try_from_http_request<T: AsRef<[u8]>>(
         request: http::Request<T>,
     ) -> Result<Self, ruma_api::error::FromHttpRequestError> {
         use std::convert::TryFrom;
diff --git a/ruma-client-api/src/r0/state/send_state_event.rs b/ruma-client-api/src/r0/state/send_state_event.rs
index 9eb7bc86..63471094 100644
--- a/ruma-client-api/src/r0/state/send_state_event.rs
+++ b/ruma-client-api/src/r0/state/send_state_event.rs
@@ -108,7 +108,7 @@ impl ruma_api::IncomingRequest for IncomingRequest {
 
     const METADATA: ruma_api::Metadata = METADATA;
 
-    fn try_from_http_request<T: bytes::Buf>(
+    fn try_from_http_request<T: AsRef<[u8]>>(
         request: http::Request<T>,
     ) -> Result<Self, ruma_api::error::FromHttpRequestError> {
         use std::{borrow::Cow, convert::TryFrom};
@@ -136,7 +136,7 @@ impl ruma_api::IncomingRequest for IncomingRequest {
         let content = {
             let event_type =
                 percent_encoding::percent_decode(path_segments[6].as_bytes()).decode_utf8()?;
-            let body: Box<RawJsonValue> = serde_json::from_reader(body.reader())?;
+            let body: Box<RawJsonValue> = serde_json::from_slice(body.as_ref())?;
 
             AnyStateEventContent::from_parts(&event_type, body)?
         };
diff --git a/ruma-client-api/src/r0/uiaa.rs b/ruma-client-api/src/r0/uiaa.rs
index 81d9780a..f59bab42 100644
--- a/ruma-client-api/src/r0/uiaa.rs
+++ b/ruma-client-api/src/r0/uiaa.rs
@@ -2,7 +2,6 @@
 
 use std::{collections::BTreeMap, fmt};
 
-use bytes::Buf;
 use ruma_api::{
     error::{IntoHttpError, ResponseDeserializationError},
     EndpointError, OutgoingResponse,
@@ -10,7 +9,7 @@ use ruma_api::{
 use ruma_serde::Outgoing;
 use serde::{Deserialize, Serialize};
 use serde_json::{
-    from_reader as from_json_reader, to_vec as to_json_vec, value::RawValue as RawJsonValue,
+    from_slice as from_json_slice, to_vec as to_json_vec, value::RawValue as RawJsonValue,
     Value as JsonValue,
 };
 
@@ -137,11 +136,11 @@ impl From<MatrixError> for UiaaResponse {
 }
 
 impl EndpointError for UiaaResponse {
-    fn try_from_http_response<T: Buf>(
+    fn try_from_http_response<T: AsRef<[u8]>>(
         response: http::Response<T>,
     ) -> Result<Self, ResponseDeserializationError> {
         if response.status() == http::StatusCode::UNAUTHORIZED {
-            Ok(UiaaResponse::AuthResponse(from_json_reader(response.into_body().reader())?))
+            Ok(UiaaResponse::AuthResponse(from_json_slice(response.body().as_ref())?))
         } else {
             MatrixError::try_from_http_response(response).map(From::from)
         }
diff --git a/ruma-client/src/lib.rs b/ruma-client/src/lib.rs
index abb85e01..de194313 100644
--- a/ruma-client/src/lib.rs
+++ b/ruma-client/src/lib.rs
@@ -373,7 +373,9 @@ impl Client {
         let hyper_response = client.hyper.request(http_request.map(hyper::Body::from)).await?;
         let (head, body) = hyper_response.into_parts();
 
-        let full_body = hyper::body::aggregate(body).await?;
+        // FIXME: Use aggregate instead of to_bytes once serde_json can parse from a reader at a
+        // comparable speed as reading from a slice: https://github.com/serde-rs/json/issues/160
+        let full_body = hyper::body::to_bytes(body).await?;
         let full_response = HttpResponse::from_parts(head, full_body);
 
         Ok(ruma_api::IncomingResponse::try_from_http_response(full_response)?)
diff --git a/ruma-serde-macros/src/display_as_ref_str.rs b/ruma-serde-macros/src/display_as_ref_str.rs
index b3180387..e521c183 100644
--- a/ruma-serde-macros/src/display_as_ref_str.rs
+++ b/ruma-serde-macros/src/display_as_ref_str.rs
@@ -6,7 +6,7 @@ pub fn expand_display_as_ref_str(ident: &Ident) -> syn::Result<TokenStream> {
         #[automatically_derived]
         impl ::std::fmt::Display for #ident {
             fn fmt(&self, f: &mut ::std::fmt::Formatter<'_>) -> ::std::fmt::Result {
-                f.write_str(<Self as ::std::convert::AsRef<::std::primitive::str>>::as_ref(self))
+                f.write_str(::std::convert::AsRef::<::std::primitive::str>::as_ref(self))
             }
         }
     })
diff --git a/ruma-serde-macros/src/serialize_as_ref_str.rs b/ruma-serde-macros/src/serialize_as_ref_str.rs
index b179ecf6..14c79e81 100644
--- a/ruma-serde-macros/src/serialize_as_ref_str.rs
+++ b/ruma-serde-macros/src/serialize_as_ref_str.rs
@@ -13,8 +13,7 @@ pub fn expand_serialize_as_ref_str(ident: &Ident) -> syn::Result<TokenStream> {
             where
                 S: #ruma_serde::exports::serde::ser::Serializer,
             {
-                <Self as ::std::convert::AsRef<::std::primitive::str>>::as_ref(self)
-                    .serialize(serializer)
+                ::std::convert::AsRef::<::std::primitive::str>::as_ref(self).serialize(serializer)
             }
         }
     })