@@ -28,10 +28,11 @@
  * @brief A class for storing and manipulating arbitrary data in an array.
  */
 @interface OFMutableData: OFData
 {
 	size_t _capacity;
+	OF_RESERVE_IVARS(4)
 }
 
 /*!
  * @brief All items of the OFMutableData as a C array.
  *