@@ -19,11 +19,11 @@
 OF_ASSUME_NONNULL_BEGIN
 
 @class OFStream;
 
 @interface OFTarArchiveEntry ()
-- (instancetype)of_initWithHeader: (char [_Nonnull 512])header
+- (instancetype)of_initWithHeader: (unsigned char [_Nonnull 512])header
     OF_METHOD_FAMILY(init);
 - (void)of_writeToStream: (OFStream *)stream;
 @end
 
 OF_ASSUME_NONNULL_END