@@ -14,10 +14,12 @@
  * file.
  */
 
 #import "OFObject.h"
 
+OF_ASSUME_NONNULL_BEGIN
+
 @class OFString;
 #ifndef DOXYGEN
 @class OFArray OF_GENERIC(ObjectType);
 @class OFMutableArray OF_GENERIC(ObjectType);
 #endif
@@ -164,15 +166,17 @@
  * @brief Returns a backtrace of when the exception was created or nil if no
  *	  backtrace is available.
  *
  * @return A backtrace of when the exception was created
  */
-- (OFArray*)backtrace;
+- (nullable OFArray*)backtrace;
 @end
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 extern OFString* of_strerror(int errNo);
 #ifdef __cplusplus
 }
 #endif
+
+OF_ASSUME_NONNULL_END