diff --git a/build.ps1 b/build.ps1
index c48bf717..3d127a39 100644
--- a/build.ps1
+++ b/build.ps1
@@ -96,4 +96,4 @@ Dir $iconvLib\libiconv* | Copy-Item -Force -Destination {Join-Path $iconvLib ($_
 BundleRelease "iconv-1.14.$distname" (dir $iconvLib\iconv_a*) (dir $iconvInc\*)
 BundleRelease "libxml2-2.9.12-1.$distname" (dir $xmlLib\*) (Get-Item $xmlInc\libxml)
 BundleRelease "libxslt-1.1.34.$distname" (dir .\libxslt\win32\bin.msvc\*) (Get-Item .\libxslt\libxslt,.\libxslt\libexslt)
-BundleRelease "zlib-1.2.11.$distname" (Get-Item .\zlib\*.*) (Get-Item .\zlib\zconf.h,.\zlib\zlib.h)
+BundleRelease "zlib-1.2.12.$distname" (Get-Item .\zlib\*.*) (Get-Item .\zlib\zconf.h,.\zlib\zlib.h)
diff --git a/zlib b/zlib
index d227f523..18712b93 160000
--- a/zlib
+++ b/zlib
@@ -1 +1 @@
-Subproject commit d227f523aac938c31d4930a85a01298eeba65c51
+Subproject commit 18712b93f10b8dad9db67d892f22d9b433b17e6d