@@ -20,10 +20,12 @@
 # import <ObjFW/OFString.h>
 #endif
 
 #import "OFBridging.h"
 
+OF_ASSUME_NONNULL_BEGIN
+
 /*!
  * @category OFString (NSObject) \
  *	     OFString+NSObject.h ObjFW-Bridge/OFString+NSObject.h
  *
  * @brief Support for bridging OFStrings to NSStrings.
@@ -32,5 +34,7 @@
  * handling UCS-4 properly (a character of NSString is only 2 bytes, while a
  * character of OFString is 4).
  */
 @interface OFString (NSObject) <OFBridging>
 @end
+
+OF_ASSUME_NONNULL_END