diff --git a/testing/matrix-sdk-test/Cargo.toml b/testing/matrix-sdk-test/Cargo.toml
index d87a394cf..080cea820 100644
--- a/testing/matrix-sdk-test/Cargo.toml
+++ b/testing/matrix-sdk-test/Cargo.toml
@@ -22,8 +22,9 @@ insta = { workspace = true }
 matrix-sdk-common = { path = "../../crates/matrix-sdk-common" }
 matrix-sdk-test-macros = { version = "0.7.0", path = "../matrix-sdk-test-macros" }
 once_cell = { workspace = true }
-# Enabling the unstable feature for polls support.
-ruma = { workspace = true, features = ["rand", "unstable-msc3381"] }
+# Enable the unstable feature for polls support.
+# "client-api-s" enables need the "server" feature of ruma-client-api, which is needed to serialize Response objects to JSON.
+ruma = { workspace = true, features = ["client-api-s", "rand", "unstable-msc3381"] }
 serde = { workspace = true }
 serde_json = { workspace = true }
 
diff --git a/testing/matrix-sdk-test/src/lib.rs b/testing/matrix-sdk-test/src/lib.rs
index 5a3c5d721..8b80e4ad7 100644
--- a/testing/matrix-sdk-test/src/lib.rs
+++ b/testing/matrix-sdk-test/src/lib.rs
@@ -2,7 +2,9 @@ use http::Response;
 pub use matrix_sdk_test_macros::async_test;
 use once_cell::sync::Lazy;
 use ruma::{
-    api::{client::sync::sync_events::v3::Response as SyncResponse, IncomingResponse},
+    api::{
+        client::sync::sync_events::v3::Response as SyncResponse, IncomingResponse, OutgoingResponse,
+    },
     room_id, user_id, RoomId, UserId,
 };
 use serde_json::Value as JsonValue;
@@ -169,3 +171,13 @@ pub fn ruma_response_from_json<ResponseType: IncomingResponse>(
         Response::builder().status(200).body(json_bytes).expect("Failed to build HTTP response");
     ResponseType::try_from_http_response(http_response).expect("Can't parse the response json")
 }
+
+/// Serialise a typed Ruma [`OutgoingResponse`] object to JSON.
+pub fn ruma_response_to_json<ResponseType: OutgoingResponse>(
+    response: ResponseType,
+) -> serde_json::Value {
+    let http_response: Response<Vec<u8>> =
+        response.try_into_http_response().expect("Failed to build HTTP response");
+    let json_bytes = http_response.into_body();
+    serde_json::from_slice(&json_bytes).expect("Can't parse the response JSON")
+}
diff --git a/testing/matrix-sdk-test/src/test_json/keys_query_sets.rs b/testing/matrix-sdk-test/src/test_json/keys_query_sets.rs
index 34282b745..c3d75bd47 100644
--- a/testing/matrix-sdk-test/src/test_json/keys_query_sets.rs
+++ b/testing/matrix-sdk-test/src/test_json/keys_query_sets.rs
@@ -7,7 +7,7 @@ use serde_json::{json, Value};
 
 use super::keys_query::{keys_query, master_keys, KeysQueryUser};
 use crate::{
-    ruma_response_from_json,
+    ruma_response_from_json, ruma_response_to_json,
     test_json::keys_query::{device_keys_payload, self_signing_keys},
 };
 
@@ -99,10 +99,14 @@ impl KeyDistributionTestData {
             }
         });
 
+        let response: KeyQueryResponse = ruma_response_from_json(&data);
         with_settings!({sort_maps => true}, {
-            assert_json_snapshot!("KeyDistributionTestData::me_keys_query_response", data);
+            assert_json_snapshot!(
+                "KeyDistributionTestData::me_keys_query_response",
+                ruma_response_to_json(response.clone()),
+            );
         });
-        ruma_response_from_json(&data)
+        response
     }
 
     /// Dan has cross-signing setup, one device is cross signed `JHPUERYQUW`,
@@ -204,11 +208,14 @@ impl KeyDistributionTestData {
                 }
         });
 
+        let response: KeyQueryResponse = ruma_response_from_json(&data);
         with_settings!({sort_maps => true}, {
-            assert_json_snapshot!("KeyDistributionTestData::dan_keys_query_response", data);
+            assert_json_snapshot!(
+                "KeyDistributionTestData::dan_keys_query_response",
+                ruma_response_to_json(response.clone()),
+            );
         });
-
-        ruma_response_from_json(&data)
+        response
     }
 
     /// Same as `dan_keys_query_response` but `FRGNMZVOKA` was removed.
@@ -291,14 +298,14 @@ impl KeyDistributionTestData {
                 }
         });
 
+        let response: KeyQueryResponse = ruma_response_from_json(&data);
         with_settings!({sort_maps => true}, {
             assert_json_snapshot!(
                 "KeyDistributionTestData::dan_keys_query_response_device_loggedout",
-                data
+                ruma_response_to_json(response.clone()),
             );
         });
-
-        ruma_response_from_json(&data)
+        response
     }
 
     /// Dave is a user that has not enabled cross-signing
@@ -646,10 +653,14 @@ impl VerificationViolationTestData {
             }
         });
 
+        let response: KeyQueryResponse = ruma_response_from_json(&data);
         with_settings!({sort_maps => true}, {
-            assert_json_snapshot!("VerificationViolationTestData::own_keys_query_response_1", data);
+            assert_json_snapshot!(
+                "VerificationViolationTestData::own_keys_query_response_1",
+                ruma_response_to_json(response.clone()),
+            );
         });
-        ruma_response_from_json(&data)
+        response
     }
 
     /// A second `/keys/query` response for Alice, containing a *different* set
diff --git a/testing/matrix-sdk-test/src/test_json/snapshots/matrix_sdk_test__test_json__keys_query_sets__KeyDistributionTestData::dan_keys_query_response.snap b/testing/matrix-sdk-test/src/test_json/snapshots/matrix_sdk_test__test_json__keys_query_sets__KeyDistributionTestData::dan_keys_query_response.snap
index 83fe4ed78..cbba19a00 100644
--- a/testing/matrix-sdk-test/src/test_json/snapshots/matrix_sdk_test__test_json__keys_query_sets__KeyDistributionTestData::dan_keys_query_response.snap
+++ b/testing/matrix-sdk-test/src/test_json/snapshots/matrix_sdk_test__test_json__keys_query_sets__KeyDistributionTestData::dan_keys_query_response.snap
@@ -1,6 +1,6 @@
 ---
 source: testing/matrix-sdk-test/src/test_json/keys_query_sets.rs
-expression: data
+expression: ruma_response_to_json(response.clone())
 ---
 {
   "device_keys": {
@@ -42,7 +42,6 @@ expression: data
       }
     }
   },
-  "failures": {},
   "master_keys": {
     "@dan:localhost": {
       "keys": {
diff --git a/testing/matrix-sdk-test/src/test_json/snapshots/matrix_sdk_test__test_json__keys_query_sets__KeyDistributionTestData::dan_keys_query_response_device_loggedout.snap b/testing/matrix-sdk-test/src/test_json/snapshots/matrix_sdk_test__test_json__keys_query_sets__KeyDistributionTestData::dan_keys_query_response_device_loggedout.snap
index 67e66315a..e2a383892 100644
--- a/testing/matrix-sdk-test/src/test_json/snapshots/matrix_sdk_test__test_json__keys_query_sets__KeyDistributionTestData::dan_keys_query_response_device_loggedout.snap
+++ b/testing/matrix-sdk-test/src/test_json/snapshots/matrix_sdk_test__test_json__keys_query_sets__KeyDistributionTestData::dan_keys_query_response_device_loggedout.snap
@@ -1,6 +1,6 @@
 ---
 source: testing/matrix-sdk-test/src/test_json/keys_query_sets.rs
-expression: data
+expression: ruma_response_to_json(response.clone())
 ---
 {
   "device_keys": {
@@ -25,7 +25,6 @@ expression: data
       }
     }
   },
-  "failures": {},
   "master_keys": {
     "@dan:localhost": {
       "keys": {