diff --git a/CHANGES b/CHANGES
index 67cd88c1d898dac7ed24ce8975927ff098467c39..0d784d426318cc60fac85fc8f67f869c39deb842 100644
--- a/CHANGES
+++ b/CHANGES
@@ -77,6 +77,16 @@
      opaque EVP_CIPHER_CTX handling.
      [Steve Henson]
 
+  *) Fixes and enhancements to zlib compression code. We now only use
+     "zlib1.dll" and use the default __cdecl calling convention on Win32
+     to conform with the standards mentioned here:
+           http://www.zlib.net/DLL_FAQ.txt
+     Static zlib linking now works on Windows and the new --with-zlib-include
+     --with-zlib-lib options to Configure can be used to supply the location
+     of the headers and library. Gracefully handle case where zlib library
+     can't be loaded.
+     [Steve Henson]
+
   *) Several fixes and enhancements to the OID generation code. The old code
      sometimes allowed invalid OIDs (1.X for X >= 40 for example), couldn't
      handle numbers larger than ULONG_MAX, truncated printing and had a
diff --git a/Configure b/Configure
index bfff183e5c5578d0672edebde113bc62c1c313de..561218717c22d474b8c0cc2d33ae7ea64733fee0 100755
--- a/Configure
+++ b/Configure
@@ -748,6 +748,10 @@ PROCESS_ARGS:
 				{
 				$withargs{"krb5-".$1}=$2;
 				}
+			elsif (/^--with-zlib-(lib|include)=(.*)$/)
+				{
+				$withargs{"zlib-".$1}=$2;
+				}
 			else
 				{
 				print STDERR $usage;
@@ -1304,6 +1308,8 @@ while (<IN>)
 	s/^PERL=.*/PERL= $perl/;
 	s/^KRB5_INCLUDES=.*/KRB5_INCLUDES=$withargs{"krb5-include"}/;
 	s/^LIBKRB5=.*/LIBKRB5=$withargs{"krb5-lib"}/;
+	s/^LIBZLIB=.*/LIBZLIB=$withargs{"zlib-lib"}/;
+	s/^ZLIB_INCLUDE=.*/ZLIB_INCLUDE=$withargs{"zlib-include"}/;
 	s/^SHLIB_TARGET=.*/SHLIB_TARGET=$shared_target/;
 	s/^SHLIB_MARK=.*/SHLIB_MARK=$shared_mark/;
 	s/^SHARED_LIBS=.*/SHARED_LIBS=\$(SHARED_CRYPTO) \$(SHARED_SSL)/ if (!$no_shared);
diff --git a/Makefile.org b/Makefile.org
index a1f6ce21956a6489a0b44d5393f9a03e388bea27..01014a8e2681606ec43c4378435a3640708cfaaf 100644
--- a/Makefile.org
+++ b/Makefile.org
@@ -100,6 +100,10 @@ RMD160_ASM_OBJ=
 KRB5_INCLUDES=
 LIBKRB5=
 
+# Zlib stuff
+ZLIB_INCLUDE=
+LIBZLIB=
+
 DIRS=   crypto ssl engines apps test tools
 SHLIBDIRS= crypto ssl
 
diff --git a/crypto/comp/c_zlib.c b/crypto/comp/c_zlib.c
index 1cd1a296af6bc2d324058523f1d53fb8b28aedfd..941b807eb39149f2d1e3fae2378676f6c8734407 100644
--- a/crypto/comp/c_zlib.c
+++ b/crypto/comp/c_zlib.c
@@ -67,46 +67,25 @@ static COMP_METHOD zlib_stateful_method={
  * When OpenSSL is built on Windows, we do not want to require that
  * the ZLIB.DLL be available in order for the OpenSSL DLLs to
  * work.  Therefore, all ZLIB routines are loaded at run time
- * and we do not link to a .LIB file.
+ * and we do not link to a .LIB file when ZLIB_SHARED is set.
  */
 #if defined(OPENSSL_SYS_WINDOWS) || defined(OPENSSL_SYS_WIN32)
 # include <windows.h>
-
-# define Z_CALLCONV _stdcall
-# ifndef ZLIB_SHARED
-#  define ZLIB_SHARED
-# endif
-#else
-# define Z_CALLCONV
 #endif /* !(OPENSSL_SYS_WINDOWS || OPENSSL_SYS_WIN32) */
 
 #ifdef ZLIB_SHARED
 #include <openssl/dso.h>
 
-/* Prototypes for built in stubs */
-#if 0
-static int stub_compress(Bytef *dest,uLongf *destLen,
-	const Bytef *source, uLong sourceLen);
-#endif
-static int stub_inflateEnd(z_streamp strm);
-static int stub_inflate(z_streamp strm, int flush);
-static int stub_inflateInit_(z_streamp strm, const char * version,
-	int stream_size);
-static int stub_deflateEnd(z_streamp strm);
-static int stub_deflate(z_streamp strm, int flush);
-static int stub_deflateInit_(z_streamp strm, int level,
-	const char * version, int stream_size);
-
 /* Function pointers */
-typedef int (Z_CALLCONV *compress_ft)(Bytef *dest,uLongf *destLen,
+typedef int (*compress_ft)(Bytef *dest,uLongf *destLen,
 	const Bytef *source, uLong sourceLen);
-typedef int (Z_CALLCONV *inflateEnd_ft)(z_streamp strm);
-typedef int (Z_CALLCONV *inflate_ft)(z_streamp strm, int flush);
-typedef int (Z_CALLCONV *inflateInit__ft)(z_streamp strm,
+typedef int (*inflateEnd_ft)(z_streamp strm);
+typedef int (*inflate_ft)(z_streamp strm, int flush);
+typedef int (*inflateInit__ft)(z_streamp strm,
 	const char * version, int stream_size);
-typedef int (Z_CALLCONV *deflateEnd_ft)(z_streamp strm);
-typedef int (Z_CALLCONV *deflate_ft)(z_streamp strm, int flush);
-typedef int (Z_CALLCONV *deflateInit__ft)(z_streamp strm, int level,
+typedef int (*deflateEnd_ft)(z_streamp strm);
+typedef int (*deflate_ft)(z_streamp strm, int flush);
+typedef int (*deflateInit__ft)(z_streamp strm, int level,
 	const char * version, int stream_size);
 static compress_ft	p_compress=NULL;
 static inflateEnd_ft	p_inflateEnd=NULL;
@@ -119,13 +98,13 @@ static deflateInit__ft	p_deflateInit_=NULL;
 static int zlib_loaded = 0;     /* only attempt to init func pts once */
 static DSO *zlib_dso = NULL;
 
-#define compress                stub_compress
-#define inflateEnd              stub_inflateEnd
-#define inflate                 stub_inflate
-#define inflateInit_            stub_inflateInit_
-#define deflateEnd              stub_deflateEnd
-#define deflate                 stub_deflate
-#define deflateInit_            stub_deflateInit_
+#define compress                p_compress
+#define inflateEnd              p_inflateEnd
+#define inflate                 p_inflate
+#define inflateInit_            p_inflateInit_
+#define deflateEnd              p_deflateEnd
+#define deflate                 p_deflate
+#define deflateInit_            p_deflateInit_
 #endif /* ZLIB_SHARED */
 
 struct zlib_state
@@ -361,16 +340,6 @@ COMP_METHOD *COMP_zlib(void)
 		{
 #if defined(OPENSSL_SYS_WINDOWS) || defined(OPENSSL_SYS_WIN32)
 		zlib_dso = DSO_load(NULL, "ZLIB1", NULL, 0);
-		if (!zlib_dso)
-			{
-			zlib_dso = DSO_load(NULL, "ZLIB", NULL, 0);
-			if (zlib_dso)
-				{
-				/* Clear the errors from the first failed
-				   DSO_load() */
-				ERR_clear_error();
-				}
-			}
 #else
 		zlib_dso = DSO_load(NULL, "z", NULL, 0);
 #endif
@@ -416,72 +385,3 @@ COMP_METHOD *COMP_zlib(void)
 	return(meth);
 	}
 
-#ifdef ZLIB_SHARED
-#if 0
-/* Stubs for each function to be dynamicly loaded */
-static int 
-stub_compress(Bytef *dest,uLongf *destLen,const Bytef *source, uLong sourceLen)
-	{
-	if (p_compress)
-		return(p_compress(dest,destLen,source,sourceLen));
-	else
-		return(Z_MEM_ERROR);
-	}
-#endif
-
-static int
-stub_inflateEnd(z_streamp strm)
-	{
-	if ( p_inflateEnd )
-		return(p_inflateEnd(strm));
-	else
-		return(Z_MEM_ERROR);
-	}
-
-static int
-stub_inflate(z_streamp strm, int flush)
-	{
-	if ( p_inflate )
-		return(p_inflate(strm,flush));
-	else
-		return(Z_MEM_ERROR);
-	}
-
-static int
-stub_inflateInit_(z_streamp strm, const char * version, int stream_size)
-	{
-	if ( p_inflateInit_ )
-		return(p_inflateInit_(strm,version,stream_size));
-	else
-		return(Z_MEM_ERROR);
-	}
-
-static int
-stub_deflateEnd(z_streamp strm)
-	{
-	if ( p_deflateEnd )
-		return(p_deflateEnd(strm));
-	else
-		return(Z_MEM_ERROR);
-	}
-
-static int
-stub_deflate(z_streamp strm, int flush)
-	{
-	if ( p_deflate )
-		return(p_deflate(strm,flush));
-	else
-		return(Z_MEM_ERROR);
-	}
-
-static int
-stub_deflateInit_(z_streamp strm, int level,
-	const char * version, int stream_size)
-	{
-	if ( p_deflateInit_ )
-		return(p_deflateInit_(strm,level,version,stream_size));
-	else
-		return(Z_MEM_ERROR);
-	}
-
-#endif /* ZLIB_SHARED */
diff --git a/util/mk1mf.pl b/util/mk1mf.pl
index 8b3d929e62f629ebffd4b4e3a6995fa911640cc7..25a3801123c6869a588108da9e3622fa2ed10253 100755
--- a/util/mk1mf.pl
+++ b/util/mk1mf.pl
@@ -12,6 +12,8 @@ $banner="\t\@echo Building OpenSSL";
 
 my $no_static_engine = 1;
 my $engines = "";
+local $zlib_opt = 0;	# 0 = no zlib, 1 = static, 2 = dynamic
+local $zlib_lib = "";
 
 
 open(IN,"<Makefile") || die "unable to open Makefile!\n";
@@ -223,6 +225,9 @@ $cflags.=" -DOPENSSL_NO_ECDH" if $no_ecdh;
 $cflags.=" -DOPENSSL_NO_ENGINE"   if $no_engine;
 $cflags.=" -DOPENSSL_NO_HW"   if $no_hw;
 
+$cflags.= " -DZLIB" if $zlib_opt;
+$cflags.= " -DZLIB_SHARED" if $zlib_opt == 2;
+
 if ($no_static_engine)
 	{
 	$cflags .= " -DOPENSSL_NO_STATIC_ENGINE";
@@ -241,6 +246,7 @@ else
 
 $ex_libs="$l_flags$ex_libs" if ($l_flags ne "");
 
+
 %shlib_ex_cflags=("SSL" => " -DOPENSSL_BUILD_SHLIBSSL",
 		  "CRYPTO" => " -DOPENSSL_BUILD_SHLIBCRYPTO");
 
@@ -285,8 +291,14 @@ for (;;)
 	if ($key eq "KRB5_INCLUDES")
 		{ $cflags .= " $val";}
 
+	if ($key eq "ZLIB_INCLUDE")
+		{ $cflags .= " -I$val";}
+
+	if ($key eq "LIBZLIB")
+		{ $zlib_lib = "$val" if $val ne "";}
+
 	if ($key eq "LIBKRB5")
-		{ $ex_libs .= " $val";}
+		{ $ex_libs .= " $val" if $val ne "";}
 
 	if ($key eq "TEST")
 		{ $test.=&var_add($dir,$val, 0); }
@@ -338,6 +350,7 @@ else
 	\$(CP) \$(O_SSL) \$(INSTALLTOP)${o}lib
 	\$(CP) \$(O_CRYPTO) \$(INSTALLTOP)${o}lib
 EOF
+	$ex_libs .= " $zlib_lib" if $zlib_opt == 1;
 	}
 
 $defs= <<"EOF";
@@ -833,7 +846,7 @@ sub do_defs
 		$ret.=$t;
 		}
 	# hack to add version info on MSVC
-	if ($shlib && ($platform eq "VC-WIN32") || ($platform eq "VC-NT"))
+	if ($shlib && (($platform eq "VC-WIN32") || ($platform eq "VC-NT")))
 		{
 		if ($var eq "CRYPTOOBJ")
 			{ $ret.="\$(OBJ_D)\\\$(CRYPTO).res "; }
@@ -1019,10 +1032,10 @@ sub read_options
 			}
 		}
 	elsif (/^no-comp$/) { $xcflags = "-DOPENSSL_NO_COMP $xcflags"; }
-	elsif (/^enable-zlib$/) { $xcflags = "-DZLIB $xcflags"; }
+	elsif (/^enable-zlib$/) { $zlib_opt = 1 if $zlib_opt == 0 }
 	elsif (/^enable-zlib-dynamic$/)
 		{
-		$xcflags = "-DZLIB_SHARED -DZLIB $xcflags";
+		$zlib_opt = 2;
 		}
 	elsif (/^no-static-engine/)
 		{
diff --git a/util/pl/VC-32.pl b/util/pl/VC-32.pl
index 0f283d80518244f4046800eead21046ae900056b..58bf9934dd0554a15cf4fcd0c66e8046f4910d2d 100644
--- a/util/pl/VC-32.pl
+++ b/util/pl/VC-32.pl
@@ -11,6 +11,8 @@ $cp='$(PERL) util/copy.pl';
 $mkdir='$(PERL) util/mkdir-p.pl';
 $rm='del';
 
+$zlib_lib="zlib1.lib";
+
 # C compiler stuff
 $cc='cl';
 if ($FLAVOR =~ /WIN64/)
@@ -146,7 +148,6 @@ if ($FLAVOR =~ /NT/)
 	$cflags.=" -DOPENSSL_SYSNAME_WINNT -DUNICODE -D_UNICODE";
 	$ex_libs="unicows.lib $ex_libs";
 	}
-
 # static library stuff
 $mklib='lib';
 $ranlib='';
@@ -278,6 +279,7 @@ sub do_lib_rule
 			$ex.=' wsock32.lib gdi32.lib advapi32.lib user32.lib';
 			$ex.=' bufferoverflowu.lib' if ($FLAVOR =~ /WIN64/);
 			}
+		$ex.=" $zlib_lib" if $zlib_opt == 1 && $target =~ /O_CRYPTO/;
 		$ret.="\t\$(LINK) \$(MLFLAGS) $efile$target $name @<<\n  \$(SHLIB_EX_OBJ) $objs $ex\n<<\n";
 		}
 	$ret.="\n";