upgraded to zlib 1.2.1
diff --git a/win32/Makefile.mingw b/win32/Makefile.mingw
index a0fb33c..415620c 100644
--- a/win32/Makefile.mingw
+++ b/win32/Makefile.mingw
@@ -79,7 +79,7 @@
 LIBS += -liconv
 endif 
 ifeq ($(WITH_ZLIB),1)
-LIBS += -lzlib
+LIBS += -lzdll
 endif
 ifeq ($(WITH_THREADS),posix)
 LIBS += -lpthreadGC
diff --git a/win32/Makefile.msvc b/win32/Makefile.msvc
index 4ea2859..3ad0dad 100644
--- a/win32/Makefile.msvc
+++ b/win32/Makefile.msvc
@@ -69,7 +69,7 @@
 LIBS = $(LIBS) iconv.lib
 !endif 
 !if "$(WITH_ZLIB)" == "1"
-LIBS = $(LIBS) zlib.lib
+LIBS = $(LIBS) zdll.lib
 !endif
 !if "$(WITH_THREADS)" == "posix"
 LIBS = $(LIBS) pthreadVC.lib