diff --git a/testing/matrix-sdk-integration-testing/src/helpers.rs b/testing/matrix-sdk-integration-testing/src/helpers.rs
index 8b71f5136fe..3a11cc16f9f 100644
--- a/testing/matrix-sdk-integration-testing/src/helpers.rs
+++ b/testing/matrix-sdk-integration-testing/src/helpers.rs
@@ -2,6 +2,7 @@ use std::{
     collections::HashMap,
     ops::Deref,
     option_env,
+    path::{Path, PathBuf},
     sync::{Arc, Mutex as StdMutex},
     time::Duration,
 };
@@ -21,9 +22,14 @@ use tokio::sync::Mutex;
 
 static USERS: Lazy<Mutex<HashMap<String, (Client, TempDir)>>> = Lazy::new(Mutex::default);
 
+enum SqlitePath {
+    Random,
+    Path(PathBuf),
+}
+
 pub struct TestClientBuilder {
     username: String,
-    use_sqlite: bool,
+    use_sqlite_dir: Option<SqlitePath>,
     encryption_settings: EncryptionSettings,
     http_proxy: Option<String>,
 }
@@ -32,7 +38,7 @@ impl TestClientBuilder {
     pub fn new(username: impl Into<String>) -> Self {
         Self {
             username: username.into(),
-            use_sqlite: false,
+            use_sqlite_dir: None,
             encryption_settings: Default::default(),
             http_proxy: None,
         }
@@ -45,7 +51,16 @@ impl TestClientBuilder {
     }
 
     pub fn use_sqlite(mut self) -> Self {
-        self.use_sqlite = true;
+        self.use_sqlite_dir = Some(SqlitePath::Random);
+        self
+    }
+
+    /// Create or re-use a Sqlite store (with no passphrase) in the supplied
+    /// directory. Note: this path must remain valid throughout the use of
+    /// the constructed Client, so if you created a TempDir you must hang on
+    /// to a reference to it throughout the test.
+    pub fn use_sqlite_dir(mut self, path: &Path) -> Self {
+        self.use_sqlite_dir = Some(SqlitePath::Path(path.to_owned()));
         self
     }
 
@@ -83,10 +98,14 @@ impl TestClientBuilder {
             client_builder = client_builder.proxy(proxy);
         }
 
-        let client = if self.use_sqlite {
-            client_builder.sqlite_store(tmp_dir.path(), None).build().await?
-        } else {
-            client_builder.build().await?
+        let client = match self.use_sqlite_dir {
+            None => client_builder.build().await?,
+            Some(SqlitePath::Random) => {
+                client_builder.sqlite_store(tmp_dir.path(), None).build().await?
+            }
+            Some(SqlitePath::Path(path_buf)) => {
+                client_builder.sqlite_store(&path_buf, None).build().await?
+            }
         };
 
         // safe to assume we have not registered this user yet, but ignore if we did
diff --git a/testing/matrix-sdk-integration-testing/src/tests/e2ee.rs b/testing/matrix-sdk-integration-testing/src/tests/e2ee.rs
index 5a3b3d91aaf..100b81279eb 100644
--- a/testing/matrix-sdk-integration-testing/src/tests/e2ee.rs
+++ b/testing/matrix-sdk-integration-testing/src/tests/e2ee.rs
@@ -1,4 +1,8 @@
-use std::sync::{Arc, Mutex};
+use std::{
+    path::Path,
+    sync::{Arc, Mutex},
+    time::{Duration, Instant},
+};
 
 use anyhow::Result;
 use assert_matches::assert_matches;
@@ -19,9 +23,11 @@ use matrix_sdk::{
                 SyncRoomMessageEvent,
             },
         },
+        EventId, OwnedEventId, OwnedRoomId, RoomId,
     },
-    Client,
+    Client, Room,
 };
+use tempfile::tempdir;
 use tracing::warn;
 
 use crate::helpers::{SyncTokenAwareClient, TestClientBuilder};
@@ -289,6 +295,164 @@ async fn test_mutual_sas_verification() -> Result<()> {
     Ok(())
 }
 
+struct ClientWrapper {
+    pub client: SyncTokenAwareClient,
+    events: Arc<Mutex<Vec<OwnedEventId>>>,
+}
+
+impl ClientWrapper {
+    async fn new(username: &str) -> Self {
+        Self::from_client_builder(TestClientBuilder::new(username).use_sqlite()).await
+    }
+
+    async fn with_sqlite_dir(username: &str, sqlite_dir: &Path) -> Self {
+        Self::from_client_builder(TestClientBuilder::new(username).use_sqlite_dir(sqlite_dir)).await
+    }
+
+    async fn from_client_builder(builder: TestClientBuilder) -> Self {
+        let events = Arc::new(Mutex::new(Vec::new()));
+
+        let client = SyncTokenAwareClient::new(
+            builder
+                .encryption_settings(Self::encryption_settings())
+                .build()
+                .await
+                .expect("Failed to create client"),
+        );
+
+        let events_clone = events.clone();
+        client.add_event_handler(|ev: OriginalSyncRoomMessageEvent, _: Client| async move {
+            events_clone.lock().unwrap().push(ev.event_id.clone())
+        });
+
+        Self { client, events }
+    }
+
+    fn encryption_settings() -> EncryptionSettings {
+        EncryptionSettings { auto_enable_cross_signing: true, ..Default::default() }
+    }
+
+    fn timeout() -> Duration {
+        Duration::from_secs(10)
+    }
+
+    async fn create_room(&self, invite: &[&ClientWrapper]) -> OwnedRoomId {
+        let invite = invite.iter().map(|cw| cw.client.user_id().unwrap().to_owned()).collect();
+
+        let request = assign!(CreateRoomRequest::new(), {
+            invite,
+            is_direct: true,
+        });
+
+        let room = self.client.create_room(request).await.expect("Failed to create room");
+        room.enable_encryption().await.expect("Failed to enable encryption");
+        room.room_id().to_owned()
+    }
+
+    async fn join(&self, room_id: &RoomId) {
+        let room = self.wait_until_room_exists(room_id).await;
+        room.join().await.expect("Unable to join room")
+    }
+
+    /// Wait (syncing if needed) until the room with supplied ID exists, or time out
+    async fn wait_until_room_exists(&self, room_id: &RoomId) -> Room {
+        let end_time = Instant::now() + Self::timeout();
+        while Instant::now() < end_time {
+            let room = self.client.get_room(room_id);
+            if let Some(room) = room {
+                return room;
+            }
+            self.client.sync_once().await.expect("Sync failed");
+        }
+        panic!("Timed out waiting for room {room_id} to exist");
+    }
+
+    /// Wait (syncing if needed) until the user appears in the supplied room, or time out
+    async fn wait_until_user_in_room(&self, room_id: &RoomId, other: &ClientWrapper) {
+        let room = self.wait_until_room_exists(room_id).await;
+        let user_id = other.client.user_id().unwrap();
+
+        let end_time = Instant::now() + Self::timeout();
+        while Instant::now() < end_time {
+            if room.get_member_no_sync(user_id).await.expect("get_member failed").is_some() {
+                return;
+            }
+            self.client.sync_once().await.expect("Sync failed");
+        }
+        panic!("Timed out waiting for user {user_id} to be in room {room_id}");
+    }
+
+    /// Wait (syncing if needed) until the event with this ID appears, or time out
+    async fn wait_until_received(&self, event_id: &EventId) {
+        let event_id = event_id.to_owned();
+        let end_time = Instant::now() + Self::timeout();
+        while Instant::now() < end_time {
+            if self.events.lock().unwrap().contains(&event_id) {
+                return;
+            }
+            self.client.sync_once().await.expect("Sync failed");
+        }
+        panic!("Timed out waiting for event {event_id} to be received");
+    }
+
+    /// Send a text message in the supplied room and return the event ID
+    async fn send(&self, room_id: &RoomId, message: &str) -> OwnedEventId {
+        let room = self.wait_until_room_exists(room_id).await;
+
+        room.send(RoomMessageEventContent::text_plain(message.to_owned()))
+            .await
+            .expect("Sending message failed")
+            .event_id
+            .to_owned()
+    }
+}
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 4)]
+async fn test_multiple_clients_share_crypto_state() -> Result<()> {
+    let alice_sqlite_dir = tempdir()?;
+    let alice1 = ClientWrapper::with_sqlite_dir("alice", alice_sqlite_dir.path()).await;
+    let alice2 = ClientWrapper::with_sqlite_dir("alice", alice_sqlite_dir.path()).await;
+    let bob = ClientWrapper::new("bob").await;
+
+    warn!("alice's device: {}", alice1.client.device_id().unwrap());
+    warn!("bob's device: {}", bob.client.device_id().unwrap());
+
+    // TODO: surely both alice clients share the same device ID because they are sharing the same DB?
+    //assert_eq!(alice1.client.device_id(), alice2.client.device_id());
+
+    let room_id = alice1.create_room(&[&bob]).await;
+
+    warn!("alice1 has created and enabled encryption in the room");
+
+    bob.join(&room_id).await;
+    alice1.wait_until_user_in_room(&room_id, &bob).await;
+
+    warn!("alice1 and bob are both aware of each other in the e2ee room");
+
+    let msg1 = bob.send(&room_id, "msg1_from_bob").await;
+    alice1.wait_until_received(&msg1).await;
+
+    warn!("alice1 received msg1 from bob");
+
+    let msg2 = bob.send(&room_id, "msg2_from_bob").await;
+    alice2.wait_until_received(&msg2).await;
+
+    warn!("alice2 received msg2 from bob");
+
+    let msg3 = alice1.send(&room_id, "msg3_from_alice").await;
+    bob.wait_until_received(&msg3).await;
+
+    warn!("bob received msg3 from alice1");
+
+    let msg4 = bob.send(&room_id, "msg4_from_bob").await;
+    alice1.wait_until_received(&msg4).await;
+    alice2.wait_until_received(&msg4).await;
+
+    warn!("alice1 and alice2 both received msg4 from bob");
+
+    Ok(())
+}
+
 #[tokio::test(flavor = "multi_thread", worker_threads = 4)]
 async fn test_mutual_qrcode_verification() -> Result<()> {
     let encryption_settings =