diff --git a/docs/contributing/how-to-update-third-party-library.md b/docs/contributing/how-to-update-third-party-library.md
index f2fddd8d76..ac885e2391 100644
--- a/docs/contributing/how-to-update-third-party-library.md
+++ b/docs/contributing/how-to-update-third-party-library.md
@@ -116,11 +116,12 @@ to perform an extra step after merging the new version (and before committing
 your changes):
 
 Create a temporary build directory and run libpng configure from it using
---with-libpng-prefix=wx_ option. Then run "make" (actually just "make png.lo"
-is sufficient as we don't really need to build the library) to create
-pnglibconf.h and pngprefix.h files in the build directory. And copy these
-files to src/png subdirectory of the wxWidgets source tree, overwriting the
-versions there.
+--with-libpng-prefix=wx_ option. Then run `make pnglibconf.h pngprefix.h`
+to create these files in the build directory. Next, search for the line
+containing `PNG_ZLIB_VERNUM` in the `pnglibconf.h` and set it to 0 to disable
+zlib version checks (this looks dangerous but seems to be unavoidable with the
+current build system). And then, finally, copy these files to src/png
+subdirectory of the wxWidgets source tree, overwriting the versions there.
 
 Notice that config.h generated by libpng configure is not used, we build it
 without -DHAVE_CONFIG_H as it works just fine without it on any ANSI C system
diff --git a/src/png b/src/png
index 834401fec4..8129d71d80 160000
--- a/src/png
+++ b/src/png
@@ -1 +1 @@
-Subproject commit 834401fec480a27e542c2861fc7c26700cc5c5fe
+Subproject commit 8129d71d80d1274b62949b07c4f2aef728c20fd9