diff --git a/ANNOUNCE b/ANNOUNCE
index 7320ce3f9..fcb3d8758 100644
--- a/ANNOUNCE
+++ b/ANNOUNCE
@@ -1,4 +1,4 @@
-Libpng 1.6.17rc05 - March 17, 2015
+Libpng 1.6.17rc05 - March 18, 2015
 
 This is not intended to be a public release.  It will be replaced
 within a few weeks by a public version or by another test version.
@@ -85,7 +85,10 @@ Version 1.6.17rc04 [March 16, 2015]
   Fix bug in calculation of maxbits, in png_write_sBIT, introduced
     in libpng-1.6.17beta01 (John Bowler).
 
-Version 1.6.17rc05 [March 17, 2015]
+Version 1.6.17rc05 [March 18, 2015]
+  Define PNG_FILTER_* and PNG_FILTER_VALUE_* in png.h even when WRITE
+    is not supported (John Bowler).  This fixes an error introduced in
+    libpng-1.6.17beta06.
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit
diff --git a/CHANGES b/CHANGES
index 298a5eed8..bcfea4347 100644
--- a/CHANGES
+++ b/CHANGES
@@ -5186,7 +5186,10 @@ Version 1.6.17rc04 [March 16, 2015]
   Fix bug in calculation of maxbits, in png_write_sBIT, introduced
     in libpng-1.6.17beta01 (John Bowler).
 
-Version 1.6.17rc05 [March 17, 2015]
+Version 1.6.17rc05 [March 18, 2015]
+  Define PNG_FILTER_* and PNG_FILTER_VALUE_* in png.h even when WRITE
+    is not supported (John Bowler).  This fixes an error introduced in
+    libpng-1.6.17beta06.
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit
diff --git a/png.h b/png.h
index 716d1245e..886d95eb2 100644
--- a/png.h
+++ b/png.h
@@ -1,7 +1,7 @@
 
 /* png.h - header file for PNG reference library
  *
- * libpng version 1.6.17rc05, March 17, 2015
+ * libpng version 1.6.17rc05, March 18, 2015
  *
  * Copyright (c) 1998-2015 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
@@ -12,7 +12,7 @@
  * Authors and maintainers:
  *   libpng versions 0.71, May 1995, through 0.88, January 1996: Guy Schalnat
  *   libpng versions 0.89c, June 1996, through 0.96, May 1997: Andreas Dilger
- *   libpng versions 0.97, January 1998, through 1.6.17rc05, March 17, 2015: Glenn
+ *   libpng versions 0.97, January 1998, through 1.6.17rc05, March 18, 2015: Glenn
  *   See also "Contributing Authors", below.
  *
  * Note about libpng version numbers:
@@ -246,7 +246,7 @@
  *
  * This code is released under the libpng license.
  *
- * libpng versions 1.2.6, August 15, 2004, through 1.6.17rc05, March 17, 2015, are
+ * libpng versions 1.2.6, August 15, 2004, through 1.6.17rc05, March 18, 2015, are
  * Copyright (c) 2004, 2006-2015 Glenn Randers-Pehrson, and are
  * distributed according to the same disclaimer and license as libpng-1.2.5
  * with the following individual added to the list of Contributing Authors:
@@ -358,7 +358,7 @@
  * Y2K compliance in libpng:
  * =========================
  *
- *    March 17, 2015
+ *    March 18, 2015
  *
  *    Since the PNG Development group is an ad-hoc body, we can't make
  *    an official declaration.
@@ -428,7 +428,7 @@
 /* Version information for png.h - this should match the version in png.c */
 #define PNG_LIBPNG_VER_STRING "1.6.17rc05"
 #define PNG_HEADER_VERSION_STRING \
-     " libpng version 1.6.17rc05 - March 17, 2015\n"
+     " libpng version 1.6.17rc05 - March 18, 2015\n"
 
 #define PNG_LIBPNG_VER_SONUM   16
 #define PNG_LIBPNG_VER_DLLNUM  16
@@ -1595,6 +1595,7 @@ PNG_EXPORT(66, void, png_set_crc_action, (png_structrp png_ptr, int crit_action,
  */
 PNG_EXPORT(67, void, png_set_filter, (png_structrp png_ptr, int method,
     int filters));
+#endif /* WRITE */
 
 /* Flags for png_set_filter() to say which filters to use.  The flags
  * are chosen so that they don't conflict with real filter types
@@ -1620,6 +1621,7 @@ PNG_EXPORT(67, void, png_set_filter, (png_structrp png_ptr, int method,
 #define PNG_FILTER_VALUE_PAETH 4
 #define PNG_FILTER_VALUE_LAST  5
 
+#ifdef PNG_WRITE_SUPPORTED
 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* EXPERIMENTAL */
 /* The "heuristic_method" is given by one of the PNG_FILTER_HEURISTIC_
  * defines, either the default (minimum-sum-of-absolute-differences), or