@@ -16,10 +16,12 @@
 
 #import "OFObject.h"
 
 #import "block.h"
 
+OF_ASSUME_NONNULL_BEGIN
+
 /*!
  * @class OFBlock OFBlock.h ObjFW/OFBlock.h
  *
  * @brief The class for all blocks, since all blocks are also objects.
  */
@@ -32,5 +34,7 @@
 @interface OFGlobalBlock: OFBlock
 @end
 
 @interface OFMallocBlock: OFBlock
 @end
+
+OF_ASSUME_NONNULL_END