diff --git a/pdfio-object.c b/pdfio-object.c
index 7b98b57..3829026 100644
--- a/pdfio-object.c
+++ b/pdfio-object.c
@@ -1,7 +1,7 @@
 //
 // PDF object functions for PDFio.
 //
-// Copyright © 2021-2024 by Michael R Sweet.
+// Copyright © 2021-2025 by Michael R Sweet.
 //
 // Licensed under Apache License v2.0.  See the file "LICENSE" for more
 // information.
@@ -10,13 +10,6 @@
 #include "pdfio-private.h"
 
 
-//
-// Local functions...
-//
-
-static bool	write_obj_header(pdfio_obj_t *obj);
-
-
 //
 // 'pdfioObjClose()' - Close an object, writing any data as needed to the PDF
 //                     file.
@@ -42,7 +35,7 @@ pdfioObjClose(pdfio_obj_t *obj)		// I - Object
   if (!obj->offset)
   {
     // Write the object value
-    if (!write_obj_header(obj))
+    if (!_pdfioObjWriteHeader(obj))
       return (false);
 
     // Write the "endobj" line...
@@ -195,7 +188,7 @@ pdfioObjCreateStream(
     }
   }
 
-  if (!write_obj_header(obj))
+  if (!_pdfioObjWriteHeader(obj))
     return (NULL);
 
   if (!_pdfioFilePuts(obj->pdf, "stream\n"))
@@ -582,11 +575,11 @@ _pdfioObjSetExtension(
 
 
 //
-// 'write_obj_header()' - Write the object header...
+// '_pdfioObjWriteHeader()' - Write the object header...
 //
 
-static bool				// O - `true` on success, `false` on failure
-write_obj_header(pdfio_obj_t *obj)	// I - Object
+bool					// O - `true` on success, `false` on failure
+_pdfioObjWriteHeader(pdfio_obj_t *obj)	// I - Object
 {
   obj->offset = _pdfioFileTell(obj->pdf);
 
diff --git a/pdfio-private.h b/pdfio-private.h
index 1284651..383bed4 100644
--- a/pdfio-private.h
+++ b/pdfio-private.h
@@ -1,7 +1,7 @@
 //
 // Private header file for PDFio.
 //
-// Copyright © 2021-2024 by Michael R Sweet.
+// Copyright © 2021-2025 by Michael R Sweet.
 //
 // Licensed under Apache License v2.0.  See the file "LICENSE" for more
 // information.
@@ -107,7 +107,7 @@ typedef enum _pdfio_mode_e		// Read/write mode
 typedef enum _pdfio_predictor_e		// PNG predictor constants
 {
   _PDFIO_PREDICTOR_NONE = 1,		// No predictor (default)
-  _PDFIO_PREDICTOR_TIFF2 = 2,		// TIFF2 predictor (???)
+  _PDFIO_PREDICTOR_TIFF2 = 2,		// TIFF predictor 2 (difference from left neighbor)
   _PDFIO_PREDICTOR_PNG_NONE = 10,	// PNG None predictor (same as `_PDFIO_PREDICTOR_NONE`)
   _PDFIO_PREDICTOR_PNG_SUB = 11,	// PNG Sub predictor
   _PDFIO_PREDICTOR_PNG_UP = 12,		// PNG Up predictor
@@ -384,6 +384,7 @@ extern void		_pdfioObjDelete(pdfio_obj_t *obj) _PDFIO_INTERNAL;
 extern void		*_pdfioObjGetExtension(pdfio_obj_t *obj) _PDFIO_INTERNAL;
 extern bool		_pdfioObjLoad(pdfio_obj_t *obj) _PDFIO_INTERNAL;
 extern void		_pdfioObjSetExtension(pdfio_obj_t *obj, void *data, _pdfio_extfree_t datafree) _PDFIO_INTERNAL;
+extern bool		_pdfioObjWriteHeader(pdfio_obj_t *obj) _PDFIO_INTERNAL;
 
 extern pdfio_stream_t	*_pdfioStreamCreate(pdfio_obj_t *obj, pdfio_obj_t *length_obj, size_t cbsize, pdfio_filter_t compression) _PDFIO_INTERNAL;
 extern pdfio_stream_t	*_pdfioStreamOpen(pdfio_obj_t *obj, bool decode) _PDFIO_INTERNAL;