@@ -13,9 +13,13 @@
  * LICENSE.GPLv2 or LICENSE.GPLv3 respectively included in the packaging of this
  * file.
  */
 
 #import "OFStream.h"
+
+OF_ASSUME_NONNULL_BEGIN
 
 @interface OFStream (OF_PRIVATE_CATEGORY)
 - (bool)OF_isWaitingForDelimiter;
 @end
+
+OF_ASSUME_NONNULL_END