diff --git a/cef1/patch/patch.cfg b/cef1/patch/patch.cfg
index 39d8bb680..7f0711026 100644
--- a/cef1/patch/patch.cfg
+++ b/cef1/patch/patch.cfg
@@ -16,6 +16,11 @@ patches = [
     'name': 'tools_gyp',
     'path': '../tools/gyp/',
   },
+  {
+    # http://code.google.com/p/chromiumembedded/issues/detail?id=496
+    'name': 'zlib',
+    'path': '../third_party/zlib/',
+  },
   {
     # http://code.google.com/p/chromiumembedded/issues/detail?id=364
     'name': 'spi_webcore_364',
diff --git a/cef1/patch/patches/zlib.patch b/cef1/patch/patches/zlib.patch
new file mode 100644
index 000000000..03c510a09
--- /dev/null
+++ b/cef1/patch/patches/zlib.patch
@@ -0,0 +1,13 @@
+Index: contrib/minizip/unzip.c
+===================================================================
+--- contrib/minizip/unzip.c	(revision 153668)
++++ contrib/minizip/unzip.c	(working copy)
+@@ -69,7 +69,7 @@
+ #include <string.h>
+ 
+ #ifndef NOUNCRYPT
+-        #define NOUNCRYPT
++//        #define NOUNCRYPT
+ #endif
+ 
+ #if defined(USE_SYSTEM_ZLIB)
diff --git a/cef3/patch/patch.cfg b/cef3/patch/patch.cfg
index a2229a76b..d0d90672a 100644
--- a/cef3/patch/patch.cfg
+++ b/cef3/patch/patch.cfg
@@ -31,6 +31,11 @@ patches = [
     'name': 'window_impl_642',
     'path': '../ui/base/win/',
   },
+  {
+    # http://code.google.com/p/chromiumembedded/issues/detail?id=496
+    'name': 'zlib',
+    'path': '../third_party/zlib/',
+  },
   {
     # http://code.google.com/p/chromiumembedded/issues/detail?id=364
     'name': 'spi_webcore_364',
diff --git a/cef3/patch/patches/zlib.patch b/cef3/patch/patches/zlib.patch
new file mode 100644
index 000000000..03c510a09
--- /dev/null
+++ b/cef3/patch/patches/zlib.patch
@@ -0,0 +1,13 @@
+Index: contrib/minizip/unzip.c
+===================================================================
+--- contrib/minizip/unzip.c	(revision 153668)
++++ contrib/minizip/unzip.c	(working copy)
+@@ -69,7 +69,7 @@
+ #include <string.h>
+ 
+ #ifndef NOUNCRYPT
+-        #define NOUNCRYPT
++//        #define NOUNCRYPT
+ #endif
+ 
+ #if defined(USE_SYSTEM_ZLIB)