diff --git a/nufxlib-0/Makefile.dll b/nufxlib-0/Makefile.dll
index 3c15885..495d254 100755
--- a/nufxlib-0/Makefile.dll
+++ b/nufxlib-0/Makefile.dll
@@ -26,7 +26,7 @@ MY_BUILD_FLAGS=
 
 MY_LIB_FLAGS=
 !ifdef LIBZ
-MY_BUILD_FLAGS = $(MY_BUILD_FLAGS) /D "ENABLE_DEFLATE"
+MY_BUILD_FLAGS = $(MY_BUILD_FLAGS) /D "ENABLE_DEFLATE" /D "ZLIB_DLL"
 MY_LIB_FLAGS = zlib.lib $(MY_LIB_FLAGS)
 !endif
 !ifdef LIBBZ2