diff --git a/crates/matrix-sdk/src/client/builder.rs b/crates/matrix-sdk/src/client/builder.rs
index 77e5c639f..fa9b17c1f 100644
--- a/crates/matrix-sdk/src/client/builder.rs
+++ b/crates/matrix-sdk/src/client/builder.rs
@@ -239,8 +239,11 @@ impl ClientBuilder {
 
     /// All outgoing http requests will have a GET query key-value appended with
     /// `user_id` being the key and the `user_id` from the `Session` being
-    /// the value. Will error if there's no `Session`. This is called
-    /// [identity assertion] in the Matrix Application Service Spec
+    /// the value. This is called [identity assertion] in the
+    /// Matrix Application Service Spec.
+    ///
+    /// Requests that don't require authentication might not do identity
+    /// assertion.
     ///
     /// [identity assertion]: https://spec.matrix.org/unstable/application-service-api/#identity-assertion
     #[doc(hidden)]
diff --git a/crates/matrix-sdk/src/http_client.rs b/crates/matrix-sdk/src/http_client.rs
index 0d70eeb26..13b4fe25f 100644
--- a/crates/matrix-sdk/src/http_client.rs
+++ b/crates/matrix-sdk/src/http_client.rs
@@ -125,7 +125,8 @@ impl HttpClient {
         }
 
         trace!("Serializing request");
-        let request = if !config.assert_identity {
+        // We can't assert the identity without a session.
+        let request = if !config.assert_identity || session.is_none() {
             let send_access_token = if auth_scheme == AuthScheme::None && !config.force_auth {
                 // Small optimization: Don't take the session lock if we know the auth token
                 // isn't going to be used anyways.