diff --git a/LICENSE b/LICENSE
index 11338b9..ce5fe99 100644
--- a/LICENSE
+++ b/LICENSE
@@ -10,7 +10,7 @@
 
 This code is released under the libpng license.
 
-libpng versions 1.0.7, July 1, 2000 through 1.6.24beta02, June 11, 2016 are
+libpng versions 1.0.7, July 1, 2000 through 1.6.24beta02, June 23, 2016 are
 Copyright (c) 2000-2002, 2004, 2006-2016 Glenn Randers-Pehrson, are
 derived from libpng-1.0.6, and are distributed according to the same
 disclaimer and license as libpng-1.0.6 with the following individuals
@@ -127,4 +127,4 @@
 
 Glenn Randers-Pehrson
 glennrp at users.sourceforge.net
-June 11, 2016
+June 23, 2016
diff --git a/README b/README
index 040aff2..31d0f69 100644
--- a/README
+++ b/README
@@ -1,4 +1,4 @@
-README for libpng version 1.6.24beta02 - June 11, 2016 (shared library 16.0)
+README for libpng version 1.6.24beta02 - June 23, 2016 (shared library 16.0)
 See the note about version numbers near the top of png.h
 
 See INSTALL for instructions on how to install libpng.
diff --git a/contrib/libtests/pngstest.c b/contrib/libtests/pngstest.c
index 250f055..dffd7c1 100644
--- a/contrib/libtests/pngstest.c
+++ b/contrib/libtests/pngstest.c
@@ -26,15 +26,6 @@
 #  include <config.h>
 #endif
 
-/* Define the following to use this test against your installed libpng, rather
- * than the one being built here:
- */
-#ifdef PNG_FREESTANDING_TESTS
-#  include <png.h>
-#else
-#  include "../../png.h"
-#endif
-
 /* 1.6.1 added support for the configure test harness, which uses 77 to indicate
  * a skipped test, in earlier versions we need to succeed on a skipped test, so:
  */
@@ -44,6 +35,15 @@
 #  define SKIP 0
 #endif
 
+/* Define the following to use this test against your installed libpng, rather
+ * than the one being built here:
+ */
+#ifdef PNG_FREESTANDING_TESTS
+#  include <png.h>
+#else
+#  include "../../png.h"
+#endif
+
 #ifdef PNG_SIMPLIFIED_READ_SUPPORTED /* Else nothing can be done */
 #include "../tools/sRGB.h"
 
diff --git a/contrib/libtests/pngvalid.c b/contrib/libtests/pngvalid.c
index 14be8ad..7a42d13 100644
--- a/contrib/libtests/pngvalid.c
+++ b/contrib/libtests/pngvalid.c
@@ -1589,7 +1589,7 @@
          {
             if (chunkpos < chunklen-4U)
             {
-               uInt avail = (uInt)-1;
+               uInt avail = -1;
 
                if (avail > (IDAT_len-4U) - IDAT_pos)
                   avail = (uInt)/*SAFE*/((IDAT_len-4U) - IDAT_pos);
diff --git a/libpng-manual.txt b/libpng-manual.txt
index 691f2e2..1d33f6b 100644
--- a/libpng-manual.txt
+++ b/libpng-manual.txt
@@ -1,6 +1,6 @@
 libpng-manual.txt - A description on how to use and modify libpng
 
- libpng version 1.6.24beta02 - June 11, 2016
+ libpng version 1.6.24beta02 - June 23, 2016
  Updated and distributed by Glenn Randers-Pehrson
  <glennrp at users.sourceforge.net>
  Copyright (c) 1998-2016 Glenn Randers-Pehrson
@@ -11,7 +11,7 @@
 
  Based on:
 
- libpng versions 0.97, January 1998, through 1.6.24beta02 - June 11, 2016
+ libpng versions 0.97, January 1998, through 1.6.24beta02 - June 23, 2016
  Updated and distributed by Glenn Randers-Pehrson
  Copyright (c) 1998-2016 Glenn Randers-Pehrson
 
@@ -559,7 +559,7 @@
 passed in row number, and pass will always be 0.  For the interlaced case the
 same applies unless the row value is 0, in which case the row just handled was
 the last one from one of the preceding passes.  Because interlacing may skip a
-pass you cannot be sure that the preceding pass is just 'pass-1', if you really
+pass you cannot be sure that the preceding pass is just 'pass-1'; if you really
 need to know what the last pass is record (row,pass) from the callback and use
 the last recorded value each time.
 
diff --git a/libpng.3 b/libpng.3
index 8226960..f56faf1 100644
--- a/libpng.3
+++ b/libpng.3
@@ -1,4 +1,4 @@
-.TH LIBPNG 3 "June 11, 2016"
+.TH LIBPNG 3 "June 23, 2016"
 .SH NAME
 libpng \- Portable Network Graphics (PNG) Reference Library 1.6.24beta02
 .SH SYNOPSIS
@@ -510,7 +510,7 @@
 .SH LIBPNG.TXT
 libpng-manual.txt - A description on how to use and modify libpng
 
- libpng version 1.6.24beta02 - June 11, 2016
+ libpng version 1.6.24beta02 - June 23, 2016
  Updated and distributed by Glenn Randers-Pehrson
  <glennrp at users.sourceforge.net>
  Copyright (c) 1998-2016 Glenn Randers-Pehrson
@@ -521,7 +521,7 @@
 
  Based on:
 
- libpng versions 0.97, January 1998, through 1.6.24beta02 - June 11, 2016
+ libpng versions 0.97, January 1998, through 1.6.24beta02 - June 23, 2016
  Updated and distributed by Glenn Randers-Pehrson
  Copyright (c) 1998-2016 Glenn Randers-Pehrson
 
@@ -1069,7 +1069,7 @@
 passed in row number, and pass will always be 0.  For the interlaced case the
 same applies unless the row value is 0, in which case the row just handled was
 the last one from one of the preceding passes.  Because interlacing may skip a
-pass you cannot be sure that the preceding pass is just 'pass\-1', if you really
+pass you cannot be sure that the preceding pass is just 'pass\-1'; if you really
 need to know what the last pass is record (row,pass) from the callback and use
 the last recorded value each time.
 
@@ -6013,7 +6013,7 @@
 
 Thanks to Frank J. T. Wojcik for helping with the documentation.
 
-Libpng version 1.6.24beta02 - June 11, 2016:
+Libpng version 1.6.24beta02 - June 23, 2016:
 Initially created in 1995 by Guy Eric Schalnat, then of Group 42, Inc.
 Currently maintained by Glenn Randers-Pehrson (glennrp at users.sourceforge.net).
 
@@ -6038,7 +6038,7 @@
 
 This code is released under the libpng license.
 
-libpng versions 1.0.7, July 1, 2000 through 1.6.24beta02, June 11, 2016 are
+libpng versions 1.0.7, July 1, 2000 through 1.6.24beta02, June 23, 2016 are
 Copyright (c) 2000-2002, 2004, 2006-2016 Glenn Randers-Pehrson, are
 derived from libpng-1.0.6, and are distributed according to the same
 disclaimer and license as libpng-1.0.6 with the following individuals
@@ -6163,7 +6163,7 @@
 
 Glenn Randers-Pehrson
 glennrp at users.sourceforge.net
-June 11, 2016
+June 23, 2016
 
 .\" end of man page
 
diff --git a/libpngpf.3 b/libpngpf.3
index 668fb9b..65317d3 100644
--- a/libpngpf.3
+++ b/libpngpf.3
@@ -1,4 +1,4 @@
-.TH LIBPNGPF 3 "June 11, 2016"
+.TH LIBPNGPF 3 "June 23, 2016"
 .SH NAME
 libpng \- Portable Network Graphics (PNG) Reference Library 1.6.24beta02
 (private functions)
diff --git a/png.5 b/png.5
index 4cb767e..4ba51a1 100644
--- a/png.5
+++ b/png.5
@@ -1,4 +1,4 @@
-.TH PNG 5 "June 11, 2016"
+.TH PNG 5 "June 23, 2016"
 .SH NAME
 png \- Portable Network Graphics (PNG) format
 .SH DESCRIPTION
diff --git a/png.c b/png.c
index 2c4c22b..d1a94dd 100644
--- a/png.c
+++ b/png.c
@@ -775,14 +775,14 @@
 #else
 #  ifdef __STDC__
    return PNG_STRING_NEWLINE \
-      "libpng version 1.6.24beta02 - June 11, 2016" PNG_STRING_NEWLINE \
+      "libpng version 1.6.24beta02 - June 23, 2016" PNG_STRING_NEWLINE \
       "Copyright (c) 1998-2002,2004,2006-2016 Glenn Randers-Pehrson" \
       PNG_STRING_NEWLINE \
       "Copyright (c) 1996-1997 Andreas Dilger" PNG_STRING_NEWLINE \
       "Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc." \
       PNG_STRING_NEWLINE;
 #  else
-   return "libpng version 1.6.24beta02 - June 11, 2016\
+   return "libpng version 1.6.24beta02 - June 23, 2016\
       Copyright (c) 1998-2002,2004,2006-2016 Glenn Randers-Pehrson\
       Copyright (c) 1996-1997 Andreas Dilger\
       Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.";
diff --git a/png.h b/png.h
index d3fad89..542b639 100644
--- a/png.h
+++ b/png.h
@@ -1,7 +1,7 @@
 
 /* png.h - header file for PNG reference library
  *
- * libpng version 1.6.24beta02, June 11, 2016
+ * libpng version 1.6.24beta02, June 23, 2016
  *
  * Copyright (c) 1998-2002,2004,2006-2016 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 0.89, June 1996, through 0.96, May 1997: Andreas Dilger
- *   libpng versions 0.97, January 1998, through 1.6.24beta02, June 11, 2016:
+ *   libpng versions 0.97, January 1998, through 1.6.24beta02, June 23, 2016:
  *     Glenn Randers-Pehrson.
  *   See also "Contributing Authors", below.
  */
@@ -29,7 +29,7 @@
  * files that are distributed with libpng have other copyright owners and
  * are released under other open source licenses.
  *
- * libpng versions 1.0.7, July 1, 2000 through 1.6.24beta02, June 11, 2016 are
+ * libpng versions 1.0.7, July 1, 2000 through 1.6.24beta02, June 23, 2016 are
  * Copyright (c) 2000-2002, 2004, 2006-2016 Glenn Randers-Pehrson, are
  * derived from libpng-1.0.6, and are distributed according to the same
  * disclaimer and license as libpng-1.0.6 with the following individuals
@@ -245,7 +245,7 @@
  * Y2K compliance in libpng:
  * =========================
  *
- *    June 11, 2016
+ *    June 23, 2016
  *
  *    Since the PNG Development group is an ad-hoc body, we can't make
  *    an official declaration.
@@ -315,7 +315,7 @@
 /* Version information for png.h - this should match the version in png.c */
 #define PNG_LIBPNG_VER_STRING "1.6.24beta02"
 #define PNG_HEADER_VERSION_STRING \
-     " libpng version 1.6.24beta02 - June 11, 2016\n"
+     " libpng version 1.6.24beta02 - June 23, 2016\n"
 
 #define PNG_LIBPNG_VER_SONUM   16
 #define PNG_LIBPNG_VER_DLLNUM  16
diff --git a/pngconf.h b/pngconf.h
index 8c62b84..a392223 100644
--- a/pngconf.h
+++ b/pngconf.h
@@ -1,7 +1,7 @@
 
 /* pngconf.h - machine configurable file for libpng
  *
- * libpng version 1.6.24beta02, June 11, 2016
+ * libpng version 1.6.24beta02, June 23, 2016
  *
  * Copyright (c) 1998-2002,2004,2006-2015 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
diff --git a/pngstruct.h b/pngstruct.h
index c1f35ed..a2a549a 100644
--- a/pngstruct.h
+++ b/pngstruct.h
@@ -1,8 +1,8 @@
 
 /* pngstruct.h - header file for PNG reference library
  *
- * Last changed in libpng 1.6.18 [July 23, 2015]
- * Copyright (c) 1998-2002,2004,2006-2015 Glenn Randers-Pehrson
+ * Last changed in libpng 1.6.24 [(PENDING RELEASE)]
+ * Copyright (c) 1998-2002,2004,2006-2016 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
  *
@@ -249,7 +249,7 @@
    png_byte filter;           /* file filter type (always 0) */
    png_byte interlaced;       /* PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */
    png_byte pass;             /* current interlace pass (0 - 6) */
-   png_byte do_filter;        /* row filter flags (see PNG_FILTER_ below ) */
+   png_byte do_filter;        /* row filter flags (see PNG_FILTER_ in png.h ) */
    png_byte color_type;       /* color type of file */
    png_byte bit_depth;        /* bit depth of file */
    png_byte usr_bit_depth;    /* bit depth of users row: write only */
diff --git a/pngwutil.c b/pngwutil.c
index 665464b..c1751fe 100644
--- a/pngwutil.c
+++ b/pngwutil.c
@@ -2448,7 +2448,7 @@
       /* Overflow can occur in the calculation, just select the lowest set
        * filter.
        */
-      filter_to_do &= 0U-filter_to_do;
+      filter_to_do &= -filter_to_do;
    }
    else if ((filter_to_do & PNG_FILTER_NONE) != 0 &&
          filter_to_do != PNG_FILTER_NONE)
@@ -2477,7 +2477,9 @@
    /* It's the only filter so no testing is needed */
    {
       /* Passing PNG_SIZE_MAX here and below prevents the 'setup' function
-       * breaking out of the loop when lmins is exceeded.
+       * breaking out of the loop when lmins is exceeded. Optimizing
+       * compilers should notice that we don't use the returned sum, and
+       * therefore 'setup' should refrain from calculating and returning "sum".
        */
       (void) png_setup_sub_row(png_ptr, bpp, row_bytes, PNG_SIZE_MAX);
       best_row = png_ptr->try_row;
diff --git a/projects/vstudio/README.txt b/projects/vstudio/README.txt
index dff7edb..c3a0214 100644
--- a/projects/vstudio/README.txt
+++ b/projects/vstudio/README.txt
@@ -1,7 +1,7 @@
 
 VisualStudio instructions
 
-libpng version 1.6.24beta02 - June 11, 2016
+libpng version 1.6.24beta02 - June 23, 2016
 
 Copyright (c) 2010,2013,2015 Glenn Randers-Pehrson
 
diff --git a/projects/vstudio/libpng/libpng.vcxproj b/projects/vstudio/libpng/libpng.vcxproj
index 9bfb718..de7fc3c 100644
--- a/projects/vstudio/libpng/libpng.vcxproj
+++ b/projects/vstudio/libpng/libpng.vcxproj
@@ -84,7 +84,7 @@
   <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
     <ClCompile>
       <PrecompiledHeader>Use</PrecompiledHeader>
-      <WarningLevel>$(WarningLevel)</WarningLevel>
+      <WarningLevel>Level4</WarningLevel>
       <MinimalRebuild>false</MinimalRebuild>
       <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
       <BasicRuntimeChecks>EnableFastChecks</BasicRuntimeChecks>
@@ -97,9 +97,9 @@
       <BrowseInformation>true</BrowseInformation>
       <CompileAs>CompileAsC</CompileAs>
       <StringPooling>true</StringPooling>
-      <DisableSpecificWarnings>$(DisableSpecificWarnings)</DisableSpecificWarnings>
+      <DisableSpecificWarnings>4996;4127</DisableSpecificWarnings>
       <AdditionalIncludeDirectories>$(ZLibSrcDir);%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
-      <TreatWarningAsError>$(TreatWarningAsError)</TreatWarningAsError>
+      <TreatWarningAsError>true</TreatWarningAsError>
       <Optimization>Disabled</Optimization>
       <RuntimeLibrary>MultiThreadedDebugDLL</RuntimeLibrary>
     </ClCompile>
@@ -114,7 +114,7 @@
   <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug Library|Win32'">
     <ClCompile>
       <PrecompiledHeader>Use</PrecompiledHeader>
-      <WarningLevel>$(WarningLevel)</WarningLevel>
+      <WarningLevel>Level4</WarningLevel>
       <MinimalRebuild>false</MinimalRebuild>
       <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
       <Optimization>Disabled</Optimization>
@@ -128,9 +128,9 @@
       <BrowseInformation>true</BrowseInformation>
       <CompileAs>CompileAsC</CompileAs>
       <StringPooling>true</StringPooling>
-      <DisableSpecificWarnings>$(DisableSpecificWarnings)</DisableSpecificWarnings>
+      <DisableSpecificWarnings>4996;4127</DisableSpecificWarnings>
       <AdditionalIncludeDirectories>$(ZLibSrcDir);%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
-      <TreatWarningAsError>$(TreatWarningAsError)</TreatWarningAsError>
+      <TreatWarningAsError>true</TreatWarningAsError>
       <RuntimeLibrary>MultiThreadedDebug</RuntimeLibrary>
     </ClCompile>
     <Link>
@@ -140,7 +140,7 @@
   </ItemDefinitionGroup>
   <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
     <ClCompile>
-      <WarningLevel>$(WarningLevel)</WarningLevel>
+      <WarningLevel>Level4</WarningLevel>
       <PrecompiledHeader>Use</PrecompiledHeader>
       <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
       <FunctionLevelLinking>true</FunctionLevelLinking>
@@ -153,9 +153,9 @@
       <CompileAs>CompileAsC</CompileAs>
       <StringPooling>true</StringPooling>
       <MinimalRebuild>false</MinimalRebuild>
-      <DisableSpecificWarnings>$(DisableSpecificWarnings)</DisableSpecificWarnings>
+      <DisableSpecificWarnings>4996;4127</DisableSpecificWarnings>
       <AdditionalIncludeDirectories>$(ZLibSrcDir);%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
-      <TreatWarningAsError>$(TreatWarningAsError)</TreatWarningAsError>
+      <TreatWarningAsError>true</TreatWarningAsError>
       <Optimization>Full</Optimization>
     </ClCompile>
     <Link>
@@ -170,7 +170,7 @@
   </ItemDefinitionGroup>
   <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release Library|Win32'">
     <ClCompile>
-      <WarningLevel>$(WarningLevel)</WarningLevel>
+      <WarningLevel>Level4</WarningLevel>
       <PrecompiledHeader>Use</PrecompiledHeader>
       <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
       <RuntimeLibrary>MultiThreaded</RuntimeLibrary>
@@ -184,9 +184,9 @@
       <CompileAs>CompileAsC</CompileAs>
       <StringPooling>true</StringPooling>
       <MinimalRebuild>false</MinimalRebuild>
-      <DisableSpecificWarnings>$(DisableSpecificWarnings)</DisableSpecificWarnings>
+      <DisableSpecificWarnings>4996;4127</DisableSpecificWarnings>
       <AdditionalIncludeDirectories>$(ZLibSrcDir);%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
-      <TreatWarningAsError>$(TreatWarningAsError)</TreatWarningAsError>
+      <TreatWarningAsError>true</TreatWarningAsError>
       <Optimization>Full</Optimization>
       <WholeProgramOptimization>true</WholeProgramOptimization>
     </ClCompile>
diff --git a/projects/vstudio/pnglibconf/pnglibconf.vcxproj b/projects/vstudio/pnglibconf/pnglibconf.vcxproj
index efcc440..e2a232c 100644
--- a/projects/vstudio/pnglibconf/pnglibconf.vcxproj
+++ b/projects/vstudio/pnglibconf/pnglibconf.vcxproj
@@ -30,7 +30,7 @@
   </PropertyGroup>
   <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
     <ClCompile>
-      <WarningLevel>$(WarningLevel)</WarningLevel>
+      <WarningLevel>Level3</WarningLevel>
       <Optimization>MaxSpeed</Optimization>
       <FunctionLevelLinking>true</FunctionLevelLinking>
       <IntrinsicFunctions>true</IntrinsicFunctions>
diff --git a/projects/vstudio/pngstest/pngstest.vcxproj b/projects/vstudio/pngstest/pngstest.vcxproj
index 21810e3..0d2980d 100644
--- a/projects/vstudio/pngstest/pngstest.vcxproj
+++ b/projects/vstudio/pngstest/pngstest.vcxproj
@@ -76,16 +76,16 @@
   <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
     <ClCompile>
       <PrecompiledHeader>NotUsing</PrecompiledHeader>
-      <WarningLevel>$(WarningLevel)</WarningLevel>
+      <WarningLevel>Level4</WarningLevel>
       <MinimalRebuild>false</MinimalRebuild>
       <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
       <Optimization>Disabled</Optimization>
       <BasicRuntimeChecks>EnableFastChecks</BasicRuntimeChecks>
       <PreprocessorDefinitions>WIN32;_DEBUG;_CONSOLE;PNG_USE_DLL;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <AdditionalIncludeDirectories>$(ZLibSrcDir);..\..\..\scripts;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
-      <DisableSpecificWarnings>$(DisableSpecificWarnings)</DisableSpecificWarnings>
+      <DisableSpecificWarnings>4996;4127</DisableSpecificWarnings>
       <CompileAsManaged>false</CompileAsManaged>
-      <TreatWarningAsError>$(TreatWarningAsError)</TreatWarningAsError>
+      <TreatWarningAsError>true</TreatWarningAsError>
       <IntrinsicFunctions>true</IntrinsicFunctions>
       <StringPooling>true</StringPooling>
       <FunctionLevelLinking>false</FunctionLevelLinking>
@@ -109,7 +109,7 @@
   <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug Library|Win32'">
     <ClCompile>
       <PrecompiledHeader>NotUsing</PrecompiledHeader>
-      <WarningLevel>$(WarningLevel)</WarningLevel>
+      <WarningLevel>Level4</WarningLevel>
       <MinimalRebuild>false</MinimalRebuild>
       <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
       <Optimization>Disabled</Optimization>
@@ -117,9 +117,9 @@
       <RuntimeLibrary>MultiThreadedDebug</RuntimeLibrary>
       <PreprocessorDefinitions>WIN32;_DEBUG;_CONSOLE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <AdditionalIncludeDirectories>$(ZLibSrcDir);..\..\..\scripts;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
-      <DisableSpecificWarnings>$(DisableSpecificWarnings)</DisableSpecificWarnings>
+      <DisableSpecificWarnings>4996;4127</DisableSpecificWarnings>
       <CompileAsManaged>false</CompileAsManaged>
-      <TreatWarningAsError>$(TreatWarningAsError)</TreatWarningAsError>
+      <TreatWarningAsError>true</TreatWarningAsError>
       <IntrinsicFunctions>true</IntrinsicFunctions>
       <StringPooling>true</StringPooling>
       <FunctionLevelLinking>false</FunctionLevelLinking>
@@ -141,7 +141,7 @@
   </ItemDefinitionGroup>
   <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
     <ClCompile>
-      <WarningLevel>$(WarningLevel)</WarningLevel>
+      <WarningLevel>Level4</WarningLevel>
       <PrecompiledHeader>NotUsing</PrecompiledHeader>
       <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
       <Optimization>Full</Optimization>
@@ -149,9 +149,9 @@
       <IntrinsicFunctions>true</IntrinsicFunctions>
       <PreprocessorDefinitions>WIN32;NDEBUG;_CONSOLE;PNG_USE_DLL;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <AdditionalIncludeDirectories>$(ZLibSrcDir);..\..\..\scripts;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
-      <DisableSpecificWarnings>$(DisableSpecificWarnings)</DisableSpecificWarnings>
+      <DisableSpecificWarnings>4996;4127</DisableSpecificWarnings>
       <CompileAsManaged>false</CompileAsManaged>
-      <TreatWarningAsError>$(TreatWarningAsError)</TreatWarningAsError>
+      <TreatWarningAsError>true</TreatWarningAsError>
       <StringPooling>true</StringPooling>
       <MinimalRebuild>false</MinimalRebuild>
       <BrowseInformation>true</BrowseInformation>
@@ -176,7 +176,7 @@
   </ItemDefinitionGroup>
   <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release Library|Win32'">
     <ClCompile>
-      <WarningLevel>$(WarningLevel)</WarningLevel>
+      <WarningLevel>Level4</WarningLevel>
       <PrecompiledHeader>NotUsing</PrecompiledHeader>
       <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
       <Optimization>Full</Optimization>
@@ -185,9 +185,9 @@
       <IntrinsicFunctions>true</IntrinsicFunctions>
       <PreprocessorDefinitions>WIN32;NDEBUG;_CONSOLE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <AdditionalIncludeDirectories>$(ZLibSrcDir);..\..\..\scripts;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
-      <DisableSpecificWarnings>$(DisableSpecificWarnings)</DisableSpecificWarnings>
+      <DisableSpecificWarnings>4996;4127</DisableSpecificWarnings>
       <CompileAsManaged>false</CompileAsManaged>
-      <TreatWarningAsError>$(TreatWarningAsError)</TreatWarningAsError>
+      <TreatWarningAsError>true</TreatWarningAsError>
       <StringPooling>true</StringPooling>
       <MinimalRebuild>false</MinimalRebuild>
       <BrowseInformation>true</BrowseInformation>
diff --git a/projects/vstudio/pngtest/pngtest.vcxproj b/projects/vstudio/pngtest/pngtest.vcxproj
index f1df07d..bf9266f 100644
--- a/projects/vstudio/pngtest/pngtest.vcxproj
+++ b/projects/vstudio/pngtest/pngtest.vcxproj
@@ -76,16 +76,16 @@
   <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
     <ClCompile>
       <PrecompiledHeader>NotUsing</PrecompiledHeader>
-      <WarningLevel>$(WarningLevel)</WarningLevel>
+      <WarningLevel>Level4</WarningLevel>
       <MinimalRebuild>false</MinimalRebuild>
       <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
       <Optimization>Disabled</Optimization>
       <BasicRuntimeChecks>EnableFastChecks</BasicRuntimeChecks>
       <PreprocessorDefinitions>WIN32;_DEBUG;_CONSOLE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <AdditionalIncludeDirectories>$(ZLibSrcDir);..\..\..\scripts;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
-      <DisableSpecificWarnings>$(DisableSpecificWarnings)</DisableSpecificWarnings>
+      <DisableSpecificWarnings>4996</DisableSpecificWarnings>
       <CompileAsManaged>false</CompileAsManaged>
-      <TreatWarningAsError>$(TreatWarningAsError)</TreatWarningAsError>
+      <TreatWarningAsError>true</TreatWarningAsError>
       <IntrinsicFunctions>true</IntrinsicFunctions>
       <StringPooling>true</StringPooling>
       <FunctionLevelLinking>false</FunctionLevelLinking>
@@ -109,7 +109,7 @@
   <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug Library|Win32'">
     <ClCompile>
       <PrecompiledHeader>NotUsing</PrecompiledHeader>
-      <WarningLevel>$(WarningLevel)</WarningLevel>
+      <WarningLevel>Level4</WarningLevel>
       <MinimalRebuild>false</MinimalRebuild>
       <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
       <Optimization>Disabled</Optimization>
@@ -117,9 +117,9 @@
       <RuntimeLibrary>MultiThreadedDebug</RuntimeLibrary>
       <PreprocessorDefinitions>WIN32;_DEBUG;_CONSOLE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <AdditionalIncludeDirectories>$(ZLibSrcDir);..\..\..\scripts;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
-      <DisableSpecificWarnings>$(DisableSpecificWarnings)</DisableSpecificWarnings>
+      <DisableSpecificWarnings>4996</DisableSpecificWarnings>
       <CompileAsManaged>false</CompileAsManaged>
-      <TreatWarningAsError>$(TreatWarningAsError)</TreatWarningAsError>
+      <TreatWarningAsError>true</TreatWarningAsError>
       <IntrinsicFunctions>true</IntrinsicFunctions>
       <StringPooling>true</StringPooling>
       <FunctionLevelLinking>false</FunctionLevelLinking>
@@ -141,7 +141,7 @@
   </ItemDefinitionGroup>
   <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
     <ClCompile>
-      <WarningLevel>$(WarningLevel)</WarningLevel>
+      <WarningLevel>Level4</WarningLevel>
       <PrecompiledHeader>NotUsing</PrecompiledHeader>
       <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
       <Optimization>Full</Optimization>
@@ -149,9 +149,9 @@
       <IntrinsicFunctions>true</IntrinsicFunctions>
       <PreprocessorDefinitions>WIN32;NDEBUG;_CONSOLE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <AdditionalIncludeDirectories>$(ZLibSrcDir);..\..\..\scripts;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
-      <DisableSpecificWarnings>$(DisableSpecificWarnings)</DisableSpecificWarnings>
+      <DisableSpecificWarnings>4996</DisableSpecificWarnings>
       <CompileAsManaged>false</CompileAsManaged>
-      <TreatWarningAsError>$(TreatWarningAsError)</TreatWarningAsError>
+      <TreatWarningAsError>true</TreatWarningAsError>
       <StringPooling>true</StringPooling>
       <MinimalRebuild>false</MinimalRebuild>
       <BrowseInformation>true</BrowseInformation>
@@ -176,7 +176,7 @@
   </ItemDefinitionGroup>
   <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release Library|Win32'">
     <ClCompile>
-      <WarningLevel>$(WarningLevel)</WarningLevel>
+      <WarningLevel>Level4</WarningLevel>
       <PrecompiledHeader>NotUsing</PrecompiledHeader>
       <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
       <Optimization>Full</Optimization>
@@ -185,9 +185,9 @@
       <IntrinsicFunctions>true</IntrinsicFunctions>
       <PreprocessorDefinitions>WIN32;NDEBUG;_CONSOLE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <AdditionalIncludeDirectories>$(ZLibSrcDir);..\..\..\scripts;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
-      <DisableSpecificWarnings>$(DisableSpecificWarnings)</DisableSpecificWarnings>
+      <DisableSpecificWarnings>4996</DisableSpecificWarnings>
       <CompileAsManaged>false</CompileAsManaged>
-      <TreatWarningAsError>$(TreatWarningAsError)</TreatWarningAsError>
+      <TreatWarningAsError>true</TreatWarningAsError>
       <StringPooling>true</StringPooling>
       <MinimalRebuild>false</MinimalRebuild>
       <BrowseInformation>true</BrowseInformation>
diff --git a/projects/vstudio/pngunknown/pngunknown.vcxproj b/projects/vstudio/pngunknown/pngunknown.vcxproj
index 409d662..a30cc7a 100644
--- a/projects/vstudio/pngunknown/pngunknown.vcxproj
+++ b/projects/vstudio/pngunknown/pngunknown.vcxproj
@@ -76,16 +76,16 @@
   <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
     <ClCompile>
       <PrecompiledHeader>NotUsing</PrecompiledHeader>
-      <WarningLevel>$(WarningLevel)</WarningLevel>
+      <WarningLevel>Level4</WarningLevel>
       <MinimalRebuild>false</MinimalRebuild>
       <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
       <Optimization>Disabled</Optimization>
       <BasicRuntimeChecks>EnableFastChecks</BasicRuntimeChecks>
       <PreprocessorDefinitions>WIN32;_DEBUG;_CONSOLE;PNG_USE_DLL;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <AdditionalIncludeDirectories>$(ZLibSrcDir);..\..\..\scripts;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
-      <DisableSpecificWarnings>$(DisableSpecificWarnings)</DisableSpecificWarnings>
+      <DisableSpecificWarnings>4996;4127</DisableSpecificWarnings>
       <CompileAsManaged>false</CompileAsManaged>
-      <TreatWarningAsError>$(TreatWarningAsError)</TreatWarningAsError>
+      <TreatWarningAsError>true</TreatWarningAsError>
       <IntrinsicFunctions>true</IntrinsicFunctions>
       <StringPooling>true</StringPooling>
       <FunctionLevelLinking>false</FunctionLevelLinking>
@@ -109,7 +109,7 @@
   <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug Library|Win32'">
     <ClCompile>
       <PrecompiledHeader>NotUsing</PrecompiledHeader>
-      <WarningLevel>$(WarningLevel)</WarningLevel>
+      <WarningLevel>Level4</WarningLevel>
       <MinimalRebuild>false</MinimalRebuild>
       <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
       <Optimization>Disabled</Optimization>
@@ -117,9 +117,9 @@
       <RuntimeLibrary>MultiThreadedDebug</RuntimeLibrary>
       <PreprocessorDefinitions>WIN32;_DEBUG;_CONSOLE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <AdditionalIncludeDirectories>$(ZLibSrcDir);..\..\..\scripts;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
-      <DisableSpecificWarnings>$(DisableSpecificWarnings)</DisableSpecificWarnings>
+      <DisableSpecificWarnings>4996;4127</DisableSpecificWarnings>
       <CompileAsManaged>false</CompileAsManaged>
-      <TreatWarningAsError>$(TreatWarningAsError)</TreatWarningAsError>
+      <TreatWarningAsError>true</TreatWarningAsError>
       <IntrinsicFunctions>true</IntrinsicFunctions>
       <StringPooling>true</StringPooling>
       <FunctionLevelLinking>false</FunctionLevelLinking>
@@ -141,7 +141,7 @@
   </ItemDefinitionGroup>
   <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
     <ClCompile>
-      <WarningLevel>$(WarningLevel)</WarningLevel>
+      <WarningLevel>Level4</WarningLevel>
       <PrecompiledHeader>NotUsing</PrecompiledHeader>
       <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
       <Optimization>Full</Optimization>
@@ -149,9 +149,9 @@
       <IntrinsicFunctions>true</IntrinsicFunctions>
       <PreprocessorDefinitions>WIN32;NDEBUG;_CONSOLE;PNG_USE_DLL;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <AdditionalIncludeDirectories>$(ZLibSrcDir);..\..\..\scripts;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
-      <DisableSpecificWarnings>$(DisableSpecificWarnings)</DisableSpecificWarnings>
+      <DisableSpecificWarnings>4996;4127</DisableSpecificWarnings>
       <CompileAsManaged>false</CompileAsManaged>
-      <TreatWarningAsError>$(TreatWarningAsError)</TreatWarningAsError>
+      <TreatWarningAsError>true</TreatWarningAsError>
       <StringPooling>true</StringPooling>
       <MinimalRebuild>false</MinimalRebuild>
       <BrowseInformation>true</BrowseInformation>
@@ -176,7 +176,7 @@
   </ItemDefinitionGroup>
   <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release Library|Win32'">
     <ClCompile>
-      <WarningLevel>$(WarningLevel)</WarningLevel>
+      <WarningLevel>Level4</WarningLevel>
       <PrecompiledHeader>NotUsing</PrecompiledHeader>
       <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
       <Optimization>Full</Optimization>
@@ -185,9 +185,9 @@
       <IntrinsicFunctions>true</IntrinsicFunctions>
       <PreprocessorDefinitions>WIN32;NDEBUG;_CONSOLE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <AdditionalIncludeDirectories>$(ZLibSrcDir);..\..\..\scripts;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
-      <DisableSpecificWarnings>$(DisableSpecificWarnings)</DisableSpecificWarnings>
+      <DisableSpecificWarnings>4996;4127</DisableSpecificWarnings>
       <CompileAsManaged>false</CompileAsManaged>
-      <TreatWarningAsError>$(TreatWarningAsError)</TreatWarningAsError>
+      <TreatWarningAsError>true</TreatWarningAsError>
       <StringPooling>true</StringPooling>
       <MinimalRebuild>false</MinimalRebuild>
       <BrowseInformation>true</BrowseInformation>
diff --git a/projects/vstudio/pngvalid/pngvalid.vcxproj b/projects/vstudio/pngvalid/pngvalid.vcxproj
index c117d29..07cf241 100644
--- a/projects/vstudio/pngvalid/pngvalid.vcxproj
+++ b/projects/vstudio/pngvalid/pngvalid.vcxproj
@@ -76,16 +76,16 @@
   <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
     <ClCompile>
       <PrecompiledHeader>NotUsing</PrecompiledHeader>
-      <WarningLevel>$(WarningLevel)</WarningLevel>
+      <WarningLevel>Level4</WarningLevel>
       <MinimalRebuild>false</MinimalRebuild>
       <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
       <Optimization>Disabled</Optimization>
       <BasicRuntimeChecks>EnableFastChecks</BasicRuntimeChecks>
       <PreprocessorDefinitions>WIN32;_DEBUG;_CONSOLE;PNG_USE_DLL;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <AdditionalIncludeDirectories>$(ZLibSrcDir);..\..\..\scripts;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
-      <DisableSpecificWarnings>$(DisableSpecificWarnings)</DisableSpecificWarnings>
+      <DisableSpecificWarnings>4996;4127</DisableSpecificWarnings>
       <CompileAsManaged>false</CompileAsManaged>
-      <TreatWarningAsError>$(TreatWarningAsError)</TreatWarningAsError>
+      <TreatWarningAsError>true</TreatWarningAsError>
       <IntrinsicFunctions>true</IntrinsicFunctions>
       <StringPooling>true</StringPooling>
       <FunctionLevelLinking>false</FunctionLevelLinking>
@@ -109,7 +109,7 @@
   <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug Library|Win32'">
     <ClCompile>
       <PrecompiledHeader>NotUsing</PrecompiledHeader>
-      <WarningLevel>$(WarningLevel)</WarningLevel>
+      <WarningLevel>Level4</WarningLevel>
       <MinimalRebuild>false</MinimalRebuild>
       <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
       <Optimization>Disabled</Optimization>
@@ -117,9 +117,9 @@
       <RuntimeLibrary>MultiThreadedDebug</RuntimeLibrary>
       <PreprocessorDefinitions>WIN32;_DEBUG;_CONSOLE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <AdditionalIncludeDirectories>$(ZLibSrcDir);..\..\..\scripts;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
-      <DisableSpecificWarnings>$(DisableSpecificWarnings)</DisableSpecificWarnings>
+      <DisableSpecificWarnings>4996;4127</DisableSpecificWarnings>
       <CompileAsManaged>false</CompileAsManaged>
-      <TreatWarningAsError>$(TreatWarningAsError)</TreatWarningAsError>
+      <TreatWarningAsError>true</TreatWarningAsError>
       <IntrinsicFunctions>true</IntrinsicFunctions>
       <StringPooling>true</StringPooling>
       <FunctionLevelLinking>false</FunctionLevelLinking>
@@ -141,7 +141,7 @@
   </ItemDefinitionGroup>
   <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
     <ClCompile>
-      <WarningLevel>$(WarningLevel)</WarningLevel>
+      <WarningLevel>Level4</WarningLevel>
       <PrecompiledHeader>NotUsing</PrecompiledHeader>
       <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
       <Optimization>Full</Optimization>
@@ -149,9 +149,9 @@
       <IntrinsicFunctions>true</IntrinsicFunctions>
       <PreprocessorDefinitions>WIN32;NDEBUG;_CONSOLE;PNG_USE_DLL;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <AdditionalIncludeDirectories>$(ZLibSrcDir);..\..\..\scripts;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
-      <DisableSpecificWarnings>$(DisableSpecificWarnings)</DisableSpecificWarnings>
+      <DisableSpecificWarnings>4996;4127</DisableSpecificWarnings>
       <CompileAsManaged>false</CompileAsManaged>
-      <TreatWarningAsError>$(TreatWarningAsError)</TreatWarningAsError>
+      <TreatWarningAsError>true</TreatWarningAsError>
       <StringPooling>true</StringPooling>
       <MinimalRebuild>false</MinimalRebuild>
       <BrowseInformation>true</BrowseInformation>
@@ -176,7 +176,7 @@
   </ItemDefinitionGroup>
   <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release Library|Win32'">
     <ClCompile>
-      <WarningLevel>$(WarningLevel)</WarningLevel>
+      <WarningLevel>Level4</WarningLevel>
       <PrecompiledHeader>NotUsing</PrecompiledHeader>
       <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
       <Optimization>Full</Optimization>
@@ -185,9 +185,9 @@
       <IntrinsicFunctions>true</IntrinsicFunctions>
       <PreprocessorDefinitions>WIN32;NDEBUG;_CONSOLE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <AdditionalIncludeDirectories>$(ZLibSrcDir);..\..\..\scripts;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
-      <DisableSpecificWarnings>$(DisableSpecificWarnings)</DisableSpecificWarnings>
+      <DisableSpecificWarnings>4996;4127</DisableSpecificWarnings>
       <CompileAsManaged>false</CompileAsManaged>
-      <TreatWarningAsError>$(TreatWarningAsError)</TreatWarningAsError>
+      <TreatWarningAsError>true</TreatWarningAsError>
       <StringPooling>true</StringPooling>
       <MinimalRebuild>false</MinimalRebuild>
       <BrowseInformation>true</BrowseInformation>
diff --git a/projects/vstudio/zlib.props b/projects/vstudio/zlib.props
index d7a0325..a0684ae 100644
--- a/projects/vstudio/zlib.props
+++ b/projects/vstudio/zlib.props
@@ -2,7 +2,7 @@
 <!--
  * zlib.props - location of zlib source
  *
- * libpng version 1.6.24beta02 - June 11, 2016
+ * libpng version 1.6.24beta02 - June 23, 2016
  *
  * Copyright (c) 1998-2011 Glenn Randers-Pehrson
  *
@@ -41,18 +41,5 @@
          test it:
      -->
     <WindowsSDKDesktopARMSupport>true</WindowsSDKDesktopARMSupport>
-
-    <!-- The following lines provide a global (solution level) control of the
-         warnings issued by the compiler, these are used in the individual
-         project files (*/*.vcxproj) with, for zlib, some extra disables.
-
-         Different versions of Visual Studio may require different settings,
-         these settings work with Visual Studio 2013.  Just set
-         TreatWarningAsError to false to check the build without failing on
-         errors.
-     -->
-   <WarningLevel>EnableAllWarnings</WarningLevel>
-   <TreatWarningAsError>true</TreatWarningAsError>
-   <DisableSpecificWarnings>4255;4668;4710;4711;4746;4820;4996</DisableSpecificWarnings>
   </PropertyGroup>
 </Project>
diff --git a/projects/vstudio/zlib/zlib.vcxproj b/projects/vstudio/zlib/zlib.vcxproj
index 0df16db..6e5b94a 100644
--- a/projects/vstudio/zlib/zlib.vcxproj
+++ b/projects/vstudio/zlib/zlib.vcxproj
@@ -88,13 +88,11 @@
     <ClCompile>
       <PreprocessorDefinitions>WIN32;_DEBUG;_WINDOWS;Z_SOLO;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <RuntimeLibrary>MultiThreadedDebug</RuntimeLibrary>
-      <WarningLevel>$(WarningLevel)</WarningLevel>
+      <WarningLevel>TurnOffAllWarnings</WarningLevel>
       <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
       <Optimization>Disabled</Optimization>
       <BrowseInformation>true</BrowseInformation>
       <FunctionLevelLinking>true</FunctionLevelLinking>
-      <DisableSpecificWarnings>$(DisableSpecificWarnings);4127;4131;4242;4244</DisableSpecificWarnings>
-      <TreatWarningAsError>$(TreatWarningAsError)</TreatWarningAsError>
     </ClCompile>
     <Link>
       <TargetMachine>MachineX86</TargetMachine>
@@ -105,13 +103,11 @@
   <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
     <ClCompile>
       <PreprocessorDefinitions>WIN32;_DEBUG;_WINDOWS;Z_SOLO;%(PreprocessorDefinitions)</PreprocessorDefinitions>
-      <WarningLevel>$(WarningLevel)</WarningLevel>
+      <WarningLevel>TurnOffAllWarnings</WarningLevel>
       <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
       <Optimization>Disabled</Optimization>
       <BrowseInformation>true</BrowseInformation>
       <FunctionLevelLinking>true</FunctionLevelLinking>
-      <DisableSpecificWarnings>$(DisableSpecificWarnings);4127;4131;4242;4244</DisableSpecificWarnings>
-      <TreatWarningAsError>$(TreatWarningAsError)</TreatWarningAsError>
       <RuntimeLibrary>MultiThreadedDebugDLL</RuntimeLibrary>
     </ClCompile>
     <Link>
@@ -122,7 +118,7 @@
   </ItemDefinitionGroup>
   <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release Library|Win32'">
     <ClCompile>
-      <WarningLevel>$(WarningLevel)</WarningLevel>
+      <WarningLevel>Level3</WarningLevel>
       <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
       <Optimization>Full</Optimization>
       <IntrinsicFunctions>true</IntrinsicFunctions>
@@ -130,8 +126,7 @@
       <BufferSecurityCheck>false</BufferSecurityCheck>
       <BrowseInformation>true</BrowseInformation>
       <FunctionLevelLinking>true</FunctionLevelLinking>
-      <DisableSpecificWarnings>$(DisableSpecificWarnings);4127;4131;4242;4244</DisableSpecificWarnings>
-      <TreatWarningAsError>$(TreatWarningAsError)</TreatWarningAsError>
+      <TreatWarningAsError>true</TreatWarningAsError>
       <RuntimeLibrary>MultiThreaded</RuntimeLibrary>
       <PreprocessorDefinitions>WIN32;NDEBUG;_WINDOWS;Z_SOLO;%(PreprocessorDefinitions)</PreprocessorDefinitions>
     </ClCompile>
@@ -146,7 +141,7 @@
   </ItemDefinitionGroup>
   <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
     <ClCompile>
-      <WarningLevel>$(WarningLevel)</WarningLevel>
+      <WarningLevel>Level3</WarningLevel>
       <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
       <Optimization>Full</Optimization>
       <IntrinsicFunctions>true</IntrinsicFunctions>
@@ -154,8 +149,7 @@
       <BufferSecurityCheck>false</BufferSecurityCheck>
       <BrowseInformation>true</BrowseInformation>
       <FunctionLevelLinking>true</FunctionLevelLinking>
-      <DisableSpecificWarnings>$(DisableSpecificWarnings);4127;4131;4242;4244</DisableSpecificWarnings>
-      <TreatWarningAsError>$(TreatWarningAsError)</TreatWarningAsError>
+      <TreatWarningAsError>true</TreatWarningAsError>
       <PreprocessorDefinitions>WIN32;NDEBUG;_WINDOWS;Z_SOLO;%(PreprocessorDefinitions)</PreprocessorDefinitions>
     </ClCompile>
     <Link>
diff --git a/scripts/README.txt b/scripts/README.txt
index e63e283..4ebfd9b 100644
--- a/scripts/README.txt
+++ b/scripts/README.txt
@@ -1,5 +1,5 @@
 
-Makefiles for  libpng version 1.6.24beta02 - June 11, 2016
+Makefiles for  libpng version 1.6.24beta02 - June 23, 2016
 
 pnglibconf.h.prebuilt       =>  Stores configuration settings
  makefile.linux    =>  Linux/ELF makefile
diff --git a/scripts/pnglibconf.h.prebuilt b/scripts/pnglibconf.h.prebuilt
index 4fd5ce0..ce63c50 100644
--- a/scripts/pnglibconf.h.prebuilt
+++ b/scripts/pnglibconf.h.prebuilt
@@ -2,7 +2,7 @@
 
 /* pnglibconf.h - library build configuration */
 
-/* Libpng version 1.6.24beta02 - June 11, 2016 */
+/* Libpng version 1.6.24beta02 - June 23, 2016 */
 
 /* Copyright (c) 1998-2015 Glenn Randers-Pehrson */