diff --git a/crates/matrix-sdk/src/account.rs b/crates/matrix-sdk/src/account.rs
index 89c82d1c6..5d150f1d1 100644
--- a/crates/matrix-sdk/src/account.rs
+++ b/crates/matrix-sdk/src/account.rs
@@ -1177,7 +1177,7 @@ mod tests {
 
     #[async_test]
     async fn test_dont_ignore_oneself() {
-        let client = MockClientBuilder::new("https://example.org".to_owned()).build().await;
+        let client = MockClientBuilder::new(None).build().await;
 
         // It's forbidden to ignore the logged-in user.
         assert_matches!(
diff --git a/crates/matrix-sdk/src/authentication/oauth/cross_process.rs b/crates/matrix-sdk/src/authentication/oauth/cross_process.rs
index f5e8c14ac..53da17838 100644
--- a/crates/matrix-sdk/src/authentication/oauth/cross_process.rs
+++ b/crates/matrix-sdk/src/authentication/oauth/cross_process.rs
@@ -269,11 +269,7 @@ mod tests {
         // Create a client that will use sqlite databases.
 
         let tmp_dir = tempfile::tempdir()?;
-        let client = MockClientBuilder::new("https://example.org".to_owned())
-            .sqlite_store(&tmp_dir)
-            .unlogged()
-            .build()
-            .await;
+        let client = MockClientBuilder::new(None).sqlite_store(&tmp_dir).unlogged().build().await;
 
         let tokens = mock_session_tokens_with_refresh();
 
diff --git a/crates/matrix-sdk/src/authentication/oauth/tests.rs b/crates/matrix-sdk/src/authentication/oauth/tests.rs
index 51687e8d2..b1d2050d8 100644
--- a/crates/matrix-sdk/src/authentication/oauth/tests.rs
+++ b/crates/matrix-sdk/src/authentication/oauth/tests.rs
@@ -483,7 +483,7 @@ async fn test_finish_login() -> anyhow::Result<()> {
 
 #[async_test]
 async fn test_oauth_session() -> anyhow::Result<()> {
-    let client = MockClientBuilder::new("https://example.org".to_owned()).unlogged().build().await;
+    let client = MockClientBuilder::new(None).unlogged().build().await;
     let oauth = client.oauth();
 
     let tokens = mock_session_tokens_with_refresh();
diff --git a/crates/matrix-sdk/src/event_cache/room/mod.rs b/crates/matrix-sdk/src/event_cache/room/mod.rs
index 3857e3d04..a46f8b3dd 100644
--- a/crates/matrix-sdk/src/event_cache/room/mod.rs
+++ b/crates/matrix-sdk/src/event_cache/room/mod.rs
@@ -2010,7 +2010,7 @@ mod timed_tests {
 
         let event_cache_store = Arc::new(MemoryStore::new());
 
-        let client = MockClientBuilder::new("http://localhost".to_owned())
+        let client = MockClientBuilder::new(None)
             .store_config(
                 StoreConfig::new("hodlor".to_owned()).event_cache_store(event_cache_store.clone()),
             )
@@ -2084,7 +2084,7 @@ mod timed_tests {
 
         let event_cache_store = Arc::new(MemoryStore::new());
 
-        let client = MockClientBuilder::new("http://localhost".to_owned())
+        let client = MockClientBuilder::new(None)
             .store_config(
                 StoreConfig::new("hodlor".to_owned()).event_cache_store(event_cache_store.clone()),
             )
@@ -2223,7 +2223,7 @@ mod timed_tests {
             .await
             .unwrap();
 
-        let client = MockClientBuilder::new("http://localhost".to_owned())
+        let client = MockClientBuilder::new(None)
             .store_config(
                 StoreConfig::new("hodlor".to_owned()).event_cache_store(event_cache_store.clone()),
             )
@@ -2361,7 +2361,7 @@ mod timed_tests {
             .await
             .unwrap();
 
-        let client = MockClientBuilder::new("http://localhost".to_owned())
+        let client = MockClientBuilder::new(None)
             .store_config(
                 StoreConfig::new("hodlor".to_owned()).event_cache_store(event_cache_store.clone()),
             )
@@ -2482,7 +2482,7 @@ mod timed_tests {
             .await
             .unwrap();
 
-        let client = MockClientBuilder::new("http://localhost".to_owned())
+        let client = MockClientBuilder::new(None)
             .store_config(
                 StoreConfig::new("holder".to_owned()).event_cache_store(event_cache_store.clone()),
             )
@@ -2516,7 +2516,7 @@ mod timed_tests {
     async fn test_no_useless_gaps() {
         let room_id = room_id!("!galette:saucisse.bzh");
 
-        let client = MockClientBuilder::new("http://localhost".to_owned()).build().await;
+        let client = MockClientBuilder::new(None).build().await;
 
         let event_cache = client.event_cache();
         event_cache.subscribe().unwrap();
@@ -2638,7 +2638,7 @@ mod timed_tests {
     async fn test_shrink_to_last_chunk() {
         let room_id = room_id!("!galette:saucisse.bzh");
 
-        let client = MockClientBuilder::new("http://localhost".to_owned()).build().await;
+        let client = MockClientBuilder::new(None).build().await;
 
         let f = EventFactory::new().room(room_id);
 
@@ -2747,7 +2747,7 @@ mod timed_tests {
     async fn test_room_ordering() {
         let room_id = room_id!("!galette:saucisse.bzh");
 
-        let client = MockClientBuilder::new("http://localhost".to_owned()).build().await;
+        let client = MockClientBuilder::new(None).build().await;
 
         let f = EventFactory::new().room(room_id).sender(*ALICE);
 
@@ -2882,7 +2882,7 @@ mod timed_tests {
     async fn test_auto_shrink_after_all_subscribers_are_gone() {
         let room_id = room_id!("!galette:saucisse.bzh");
 
-        let client = MockClientBuilder::new("http://localhost".to_owned()).build().await;
+        let client = MockClientBuilder::new(None).build().await;
 
         let f = EventFactory::new().room(room_id);
 
@@ -2993,7 +2993,7 @@ mod timed_tests {
     async fn test_rfind_event_in_memory_by() {
         let user_id = user_id!("@mnt_io:matrix.org");
         let room_id = room_id!("!raclette:patate.ch");
-        let client = MockClientBuilder::new("http://localhost".to_owned()).build().await;
+        let client = MockClientBuilder::new(None).build().await;
 
         let event_factory = EventFactory::new().room(room_id);
 
diff --git a/crates/matrix-sdk/src/test_utils/client.rs b/crates/matrix-sdk/src/test_utils/client.rs
index 6cf230d15..e787b6aad 100644
--- a/crates/matrix-sdk/src/test_utils/client.rs
+++ b/crates/matrix-sdk/src/test_utils/client.rs
@@ -36,10 +36,13 @@ impl MockClientBuilder {
     /// Create a new [`MockClientBuilder`] connected to the given homeserver,
     /// using Matrix V1.12, and which will not attempt any network retry (by
     /// default).
-    pub(crate) fn new(homeserver: String) -> Self {
+    ///
+    /// If no homeserver is provided, `http://localhost` is used as a homeserver.
+    pub(crate) fn new(homeserver: Option<&str>) -> Self {
+        let homeserver = homeserver.unwrap_or("http://localhost");
+
         let default_builder = Client::builder()
-            .homeserver_url(&homeserver)
-            .server_versions([MatrixVersion::V1_12])
+            .homeserver_url(homeserver)
             .request_config(RequestConfig::new().disable_retry());
 
         Self {
diff --git a/crates/matrix-sdk/src/test_utils/mocks/encryption.rs b/crates/matrix-sdk/src/test_utils/mocks/encryption.rs
index f4cf4fb90..da9dcfcbc 100644
--- a/crates/matrix-sdk/src/test_utils/mocks/encryption.rs
+++ b/crates/matrix-sdk/src/test_utils/mocks/encryption.rs
@@ -96,7 +96,7 @@ impl MatrixMockServer {
             mappings.insert(auth_string, user_id.to_owned());
         }
 
-        MockClientBuilder::new(self.server.uri()).logged_in_with_token(
+        MockClientBuilder::new(Some(&self.server.uri())).logged_in_with_token(
             access_token,
             user_id.to_owned(),
             device_id.to_owned(),
diff --git a/crates/matrix-sdk/src/test_utils/mocks/mod.rs b/crates/matrix-sdk/src/test_utils/mocks/mod.rs
index a84b97a1b..9ba9860dc 100644
--- a/crates/matrix-sdk/src/test_utils/mocks/mod.rs
+++ b/crates/matrix-sdk/src/test_utils/mocks/mod.rs
@@ -180,7 +180,7 @@ impl MatrixMockServer {
     /// Creates a new [`MockClientBuilder`] configured to use this server,
     /// preconfigured with a session expected by the server endpoints.
     pub fn client_builder(&self) -> MockClientBuilder {
-        MockClientBuilder::new(self.server.uri())
+        MockClientBuilder::new(Some(&self.server.uri()))
     }
 
     /// Return the underlying [`wiremock`] server.