@@ -14,12 +14,16 @@
  * file.
  */
 
 #import "OFSHA224Or256Hash.h"
 
+OF_ASSUME_NONNULL_BEGIN
+
 /*!
  * @class OFSHA256Hash OFSHA256Hash.h ObjFW/OFSHA256Hash.h
  *
  * @brief A class which provides functions to create an SHA-256 hash.
  */
 @interface OFSHA256Hash: OFSHA224Or256Hash
 @end
+
+OF_ASSUME_NONNULL_END