@@ -17,10 +17,18 @@
 #import <Foundation/NSString.h>
 
 #import "NSBridging.h"
 
 NS_ASSUME_NONNULL_BEGIN
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+extern int _NSString_OFObject_reference;
+#ifdef __cplusplus
+}
+#endif
 
 /*!
  * @category NSString (OFObject)
  *	     NSString+OFObject.h ObjFW-Bridge/NSString+OFObject.h
  *