diff --git a/ANNOUNCE b/ANNOUNCE
index 6573d8803..47842b400 100644
--- a/ANNOUNCE
+++ b/ANNOUNCE
@@ -76,6 +76,8 @@ Version 1.6.31beta02 [July 8, 2017]
 
 Version 1.6.31beta03 [July 9, 2017]
   Updated CMakeLists.txt to add INTEL_SSE and MIPS_MSA platforms.
+  Change "int" to "png_uint_32" in intel/filter_sse2.c to prevent
+    possible integer overflow (Bug report by John Bowler).
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
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diff --git a/CHANGES b/CHANGES
index 704834314..e7834f9de 100644
--- a/CHANGES
+++ b/CHANGES
@@ -5871,6 +5871,8 @@ Version 1.6.31beta02 [July 8, 2017]
 
 Version 1.6.31beta03 [July 9, 2017]
   Updated CMakeLists.txt to add INTEL_SSE and MIPS_MSA platforms.
+  Change "int" to "png_uint_32" in intel/filter_sse2.c to prevent
+    possible integer overflow (Bug report by John Bowler).
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit
diff --git a/intel/filter_sse2_intrinsics.c b/intel/filter_sse2_intrinsics.c
index b91d8da96..86c4ea431 100644
--- a/intel/filter_sse2_intrinsics.c
+++ b/intel/filter_sse2_intrinsics.c
@@ -5,7 +5,7 @@
  * Written by Mike Klein and Matt Sarett
  * Derived from arm/filter_neon_intrinsics.c
  *
- * Last changed in libpng 1.6.29 [March 16, 2017]
+ * Last changed in libpng 1.6.31 [(PENDING RELEASE)]
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
@@ -71,7 +71,7 @@ void png_read_filter_row_sub3_sse2(png_row_infop row_info, png_bytep row,
    png_debug(1, "in png_read_filter_row_sub3_sse2");
    __m128i a, d = _mm_setzero_si128();
 
-   int rb = row_info->rowbytes;
+   png_uint_32 rb = row_info->rowbytes;
    while (rb >= 4) {
       a = d; d = load4(row);
       d = _mm_add_epi8(d, a);
@@ -100,8 +100,8 @@ void png_read_filter_row_sub4_sse2(png_row_infop row_info, png_bytep row,
    png_debug(1, "in png_read_filter_row_sub4_sse2");
    __m128i a, d = _mm_setzero_si128();
 
-   int rb = row_info->rowbytes;
-   while (rb > 0) {
+   png_uint_32 rb = row_info->rowbytes+4;
+   while (rb > 4) {
       a = d; d = load4(row);
       d = _mm_add_epi8(d, a);
       store4(row, d);
@@ -124,7 +124,7 @@ void png_read_filter_row_avg3_sse2(png_row_infop row_info, png_bytep row,
    __m128i    b;
    __m128i a, d = zero;
 
-   int rb = row_info->rowbytes;
+   png_uint_32 rb = row_info->rowbytes;
    while (rb >= 4) {
              b = load4(prev);
       a = d; d = load4(row );
@@ -173,8 +173,8 @@ void png_read_filter_row_avg4_sse2(png_row_infop row_info, png_bytep row,
    __m128i    b;
    __m128i a, d = zero;
 
-   int rb = row_info->rowbytes;
-   while (rb > 0) {
+   png_uint_32 rb = row_info->rowbytes+4;
+   while (rb > 4) {
              b = load4(prev);
       a = d; d = load4(row );
 
@@ -242,7 +242,7 @@ void png_read_filter_row_paeth3_sse2(png_row_infop row_info, png_bytep row,
    __m128i c, b = zero,
            a, d = zero;
 
-   int rb = row_info->rowbytes;
+   png_uint_32 rb = row_info->rowbytes;
    while (rb >= 4) {
       /* It's easiest to do this math (particularly, deal with pc) with 16-bit
        * intermediates.
@@ -336,8 +336,8 @@ void png_read_filter_row_paeth4_sse2(png_row_infop row_info, png_bytep row,
    __m128i c, b = zero,
            a, d = zero;
 
-   int rb = row_info->rowbytes;
-   while (rb > 0) {
+   png_uint_32 rb = row_info->rowbytes+4;
+   while (rb > 4) {
       /* It's easiest to do this math (particularly, deal with pc) with 16-bit
        * intermediates.
        */