diff --git a/lib/src/model/event_types.dart b/lib/src/model/event_types.dart
index b948c8a2..3878cb7a 100644
--- a/lib/src/model/event_types.dart
+++ b/lib/src/model/event_types.dart
@@ -81,7 +81,9 @@ abstract class EventTypes {
   static const String MegolmBackup = 'm.megolm_backup.v1';
   static const String SecretStorageDefaultKey = 'm.secret_storage.default_key';
 
-  static String secretStorageKey(String keyId) => 'm.secret_storage.key.$keyId';
+  // Also used as account data type so it needs to be uri encoded
+  static String secretStorageKey(String keyId) =>
+      Uri.encodeComponent('m.secret_storage.key.$keyId');
 
   // Spaces
   static const String spaceParent = 'm.space.parent';