diff --git a/ANNOUNCE b/ANNOUNCE
index 0dcb5dea7..194f875ab 100644
--- a/ANNOUNCE
+++ b/ANNOUNCE
@@ -1,5 +1,5 @@
 
-Libpng 1.6.7beta03 - October 14, 2013
+Libpng 1.6.7beta03 - October 17, 2013
 
 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.
@@ -72,10 +72,12 @@ Version 1.6.7beta02 [October 12, 2013]
   Make autogen.sh work with automake 1.13 as well as 1.14. Do this by always
     removing the 1.14 'compile' script but never checking for it.
 
-Version 1.6.7beta03 [October 14, 2013]
+Version 1.6.7beta03 [October 17, 2013]
   Added ARMv8 support (James Yu <james.yu at linaro.org>).  Added file
     arm/filter_neon_intrinsics.c; enable with configuration flag
     PNG_ARM_NEON_INTRINSICS.
+  Revised pngvalid to generate size images with as many filters as it can
+    manage, limited by the number of rows.
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit
diff --git a/CHANGES b/CHANGES
index e7e344495..a6e5efbdf 100644
--- a/CHANGES
+++ b/CHANGES
@@ -4686,10 +4686,12 @@ Version 1.6.7beta02 [October 12, 2013]
   Make autogen.sh work with automake 1.13 as well as 1.14. Do this by always
     removing the 1.14 'compile' script but never checking for it.
 
-Version 1.6.7beta03 [October 14, 2013]
+Version 1.6.7beta03 [October 17, 2013]
   Added ARMv8 support (James Yu <james.yu at linaro.org>).  Added file
     arm/filter_neon_intrinsics.c; enable with configuration flag
     PNG_ARM_NEON_INTRINSICS.
+  Revised pngvalid to generate size images with as many filters as it can
+    manage, limited by the number of rows.
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit
diff --git a/Makefile.am b/Makefile.am
index 05e534feb..5ac0423e1 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -324,3 +324,8 @@ uninstall-hook:
 	rm -f '$(DESTDIR)$(libdir)/libpng.sl'
 	rm -f '$(DESTDIR)$(libdir)/libpng.dylib'
 	rm -f '$(DESTDIR)$(libdir)/libpng.dll.a'
+
+# The following addition ensures that 'make all' always builds the test programs
+# too.  It used to, but some change either in libpng or configure stopped this
+# working.
+all-am: $(check_PROGRAMS)
diff --git a/contrib/libtests/pngvalid.c b/contrib/libtests/pngvalid.c
index 460fdd4c2..55ec5af4f 100644
--- a/contrib/libtests/pngvalid.c
+++ b/contrib/libtests/pngvalid.c
@@ -2945,6 +2945,12 @@ sbit_modification_init(sbit_modification *me, png_modifier *pm, png_byte sbit)
  * height of 16 rows.  The width and height are stored in the FILEID and, being
  * non-zero, indicate a size file.
  *
+ * Because the PNG filter code is typically the largest CPU consumer within
+ * libpng itself there is a tendency to attempt to optimize it.  This results in
+ * special case code which needs to be validated.  To cause this to happen the
+ * 'size' images are made to use each possible filter, in so far as this is
+ * possible for smaller images.
+ *
  * For palette image (colour type 3) multiple transform images are stored with
  * the same bit depth to allow testing of more colour combinations -
  * particularly important for testing the gamma code because libpng uses a
@@ -3660,6 +3666,7 @@ make_size_image(png_store* PNG_CONST ps, png_byte PNG_CONST colour_type,
          int npasses = npasses_from_interlace_type(pp, interlace_type);
          png_uint_32 y;
          int pass;
+         int nfilter = PNG_FILTER_VALUE_LAST;
          png_byte image[16][SIZE_ROWMAX];
 
          /* To help consistent error detection make the parts of this buffer
@@ -3713,7 +3720,22 @@ make_size_image(png_store* PNG_CONST ps, png_byte PNG_CONST colour_type,
                      continue;
                }
 
-               /* Only get to here if the row has some pixels in it. */
+               /* Only get to here if the row has some pixels in it, set the
+                * filters to 'all' for the very first row and thereafter to a
+                * single filter.  It isn't well documented, but png_set_filter
+                * does accept a filter number (per the spec) as well as a bit
+                * mask.
+                *
+                * The apparent wackiness of decrementing nfilter rather than
+                * incrementing is so that Paeth gets used in all images bigger
+                * than 1 row - it's the tricky one.
+                */
+               png_set_filter(pp, 0/*method*/,
+                  nfilter >= PNG_FILTER_VALUE_LAST ? PNG_ALL_FILTERS : nfilter);
+
+               if (nfilter-- == 0)
+                  nfilter = PNG_FILTER_VALUE_LAST-1;
+
                png_write_row(pp, row);
             }
          }