@@ -22,15 +22,15 @@
 /**
  * @class OFMethodSignature OFMethodSignature.h ObjFW/OFMethodSignature.h
  *
  * @brief A class for parsing type encodings and accessing them.
  */
+OF_SUBCLASSING_RESTRICTED
 @interface OFMethodSignature: OFObject
 {
 	char *_types;
 	OFMutableData *_typesPointers, *_offsets;
-	OF_RESERVE_IVARS(OFMethodSignature, 4)
 }
 
 /**
  * @brief The number of arguments of the method.
  */