diff --git a/packaging/nsis/Makefile.nmake b/packaging/nsis/Makefile.nmake
index e7c19f1518..43f2de7355 100644
--- a/packaging/nsis/Makefile.nmake
+++ b/packaging/nsis/Makefile.nmake
@@ -111,6 +111,7 @@ wireshark-$(WIRESHARK_TARGET_PLATFORM)-$(VERSION).exe : user-guide.chm $(NSI) $(
 	/DPANGO_LIB_DIR=$(PANGO_LIB_DIR) \
 !IFDEF NEED_LIBPNG_DLL
 	/DNEED_LIBPNG_DLL=$(NEED_LIBPNG_DLL) \
+	/DPNG_DLL=$(PNG_DLL) \
 !ENDIF
 !IFDEF NEED_LIBJPEG_DLL
 	/DNEED_LIBJPEG_DLL=$(NEED_LIBJPEG_DLL) \