@@ -21,14 +21,14 @@
  * @class OFXMLProcessingInstruction \
  *	  OFXMLProcessingInstruction.h ObjFW/OFXMLProcessingInstruction.h
  *
  * @brief A class for representing an XML processing instruction.
  */
+OF_SUBCLASSING_RESTRICTED
 @interface OFXMLProcessingInstruction: OFXMLNode
 {
 	OFString *_target, *_Nullable _text;
-	OF_RESERVE_IVARS(OFXMLProcessingInstruction, 4)
 }
 
 /**
  * @brief The target of the processing instruction.
  */