diff --git a/crates/matrix-sdk/src/encryption/mod.rs b/crates/matrix-sdk/src/encryption/mod.rs
index d7db4d095e3..234d9c0d4a3 100644
--- a/crates/matrix-sdk/src/encryption/mod.rs
+++ b/crates/matrix-sdk/src/encryption/mod.rs
@@ -1407,6 +1407,15 @@ impl Encryption {
         }
     }
 
+    /// Upload the device keys and initial set of one-tim keys to the server.
+    ///
+    /// This should only be called when the user logs in for the first time,
+    /// the method will ensure that other devices see our own device as an
+    /// end-to-end encryption enabled one.
+    ///
+    /// **Warning**: Do not use this method if we're already calling
+    /// [`Client::send_outgoing_request()`]. This method is intended for
+    /// explicitly uploading the device keys before starting a sync.
     #[cfg(feature = "experimental-oidc")]
     pub(crate) async fn ensure_device_keys_upload(&self) -> Result<()> {
         let olm = self.client.olm_machine().await;