diff --git a/ANNOUNCE b/ANNOUNCE
index 928a1e71b..70fabac86 100644
--- a/ANNOUNCE
+++ b/ANNOUNCE
@@ -1,5 +1,5 @@
 
-Libpng 1.7.0beta77 - January 12, 2016
+Libpng 1.7.0beta77 - January 13, 2016
 
 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.
@@ -1172,7 +1172,7 @@ Version 1.7.0beta76 [January 7, 2016]
   Fixed new Coverity defect, potential NULL dereference of "ps" in pngwutil.c
   Added temporary workaround for Coverity "Dead code" defect.
 
-Version 1.7.0beta77 [January 12, 2016]
+Version 1.7.0beta77 [January 13, 2016]
   Fixed new Coverity defect, another NULL dereference of "ps" in pngwutil.c
   Prevent the CMINFO optimization code from running twice on any PNG IDAT
     stream longer than 2048 bytes; the second time could overwrite bytes
@@ -1212,6 +1212,7 @@ Version 1.7.0beta77 [January 12, 2016]
     there is an unrelated bug which means that lower zlib memLevels result
     in memory corruption under some circumstances, probably less often
     than 1:1000.
+  Worked around a false-positive Coverity issue in pngvalid.c.
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit
diff --git a/CHANGES b/CHANGES
index f52562a65..6550d9e42 100644
--- a/CHANGES
+++ b/CHANGES
@@ -5471,7 +5471,7 @@ Version 1.7.0beta76 [January 7, 2016]
   Fixed new Coverity defect, potential NULL dereference of "ps" in pngwutil.c
   Added temporary workaround for Coverity "Dead code" defect.
 
-Version 1.7.0beta77 [January 12, 2016]
+Version 1.7.0beta77 [January 13, 2016]
   Fixed new Coverity defect, another NULL dereference of "ps" in pngwutil.c
   Prevent the CMINFO optimization code from running twice on any PNG IDAT
     stream longer than 2048 bytes; the second time could overwrite bytes
@@ -5511,6 +5511,7 @@ Version 1.7.0beta77 [January 12, 2016]
     there is an unrelated bug which means that lower zlib memLevels result
     in memory corruption under some circumstances, probably less often
     than 1:1000.
+  Worked around a false-positive Coverity issue in pngvalid.c.
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit
diff --git a/contrib/libtests/pngvalid.c b/contrib/libtests/pngvalid.c
index 407a0f66e..9063b69fe 100644
--- a/contrib/libtests/pngvalid.c
+++ b/contrib/libtests/pngvalid.c
@@ -309,8 +309,13 @@ static void r16(png_uint_16p p16, size_t count)
    }
 }
 
-#define R16(this)\
+#ifdef __COVERITY__
+#  define R16(this)\
+   r16(&(this), (sizeof (this))/2U/*(sizeof (png_uint_16))*/)
+#else
+#  define R16(this)\
    r16(&(this), (sizeof (this))/(sizeof (png_uint_16)))
+#endif
 
 #if defined PNG_READ_RGB_TO_GRAY_SUPPORTED ||\
     defined PNG_READ_FILLER_SUPPORTED
@@ -326,8 +331,14 @@ static void r32(png_uint_32p p32, size_t count)
    }
 }
 
-#define R32(this)\
+#ifdef __COVERITY__
+#  define R32(this)\
+   r32(&(this), (sizeof (this))/4U/*(sizeof (png_uint_32))*/)
+#else
+#  define R32(this)\
    r32(&(this), (sizeof (this))/(sizeof (png_uint_32)))
+#endif
+
 #endif /* READ_FILLER || READ_RGB_TO_GRAY */
 
 #endif /* READ || WRITE_tRNS || WRITE_FILTER */