@@ -24,16 +24,16 @@
 /**
  * @class OFInvocation OFInvocation.h ObjFW/OFInvocation.h
  *
  * @brief A class for storing and accessing invocations, and invoking them.
  */
+OF_SUBCLASSING_RESTRICTED
 @interface OFInvocation: OFObject
 {
 	OFMethodSignature *_methodSignature;
 	OFMutableArray OF_GENERIC(OFMutableData *) *_arguments;
 	OFMutableData *_returnValue;
-	OF_RESERVE_IVARS(OFInvocation, 4)
 }
 
 /**
  * @brief The method signature for the invocation.
  */