diff --git a/ChangeLog b/ChangeLog
index fd4cb849..47827d5c 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+2009-06-02  Frank Warmerdam  <warmerdam@pobox.com>
+
+	* libtiff/libtiff.def: Add TIFFUnsetField.
+
 2009-05-03  Frank Warmerdam  <warmerdam@pobox.com>
 
 	* libtiff/{tif_jpeg.c,tif_ojpeg.c,tif_getimage.c}: Fixed various
diff --git a/libtiff/libtiff.def b/libtiff/libtiff.def
index 1f1193f2..47c48e6c 100644
--- a/libtiff/libtiff.def
+++ b/libtiff/libtiff.def
@@ -140,3 +140,4 @@ EXPORTS TIFFOpen
 	TIFFSwabLong8
 	TIFFSwabArrayOfLong8
 	TIFFFindField
+	TIFFUnsetField