Index: src/3rdparty/opennurbs/opennurbs/opennurbs.pro
--- src/3rdparty/opennurbs/opennurbs/opennurbs.pro.orig
+++ src/3rdparty/opennurbs/opennurbs/opennurbs.pro
@@ -225,7 +225,7 @@ CONFIG(release, debug|release) {
 else {
     LIBS += -L../zlib/debug
 }
-LIBS += -lzlib
+LIBS += -lz
 win32 {
     #DEFINES += ON_DLL_EXPORTS ON_COMPILING_OPENNURBS NDEBUG
     DEFINES += ON_COMPILING_OPENNURBS NDEBUG
