diff --git a/backend_qt/backend_qt.pro b/backend_qt/backend_qt.pro
index 5340ca10..1ea96eb8 100644
--- a/backend_qt/backend_qt.pro
+++ b/backend_qt/backend_qt.pro
@@ -19,7 +19,7 @@ TARGET = QtZint
 INCLUDEPATH += ../backend
 
 #EDIT THIS !!!!
-DEFINES += ZINT_VERSION="\\\"2.5.0\\\""
+DEFINES += ZINT_VERSION="\\\"2.5.1\\\""
 
 !contains(DEFINES, NO_PNG) {
     INCLUDEPATH += ../../lpng
diff --git a/frontend_qt/frontend_qt.pro b/frontend_qt/frontend_qt.pro
index ba975631..6084217e 100644
--- a/frontend_qt/frontend_qt.pro
+++ b/frontend_qt/frontend_qt.pro
@@ -61,9 +61,9 @@ QMAKE_LIBDIR += ../backend_qt/release
 
 !contains(DEFINES, NO_PNG) {
 # Win
-    win32:LIBS += -llibpng16 -zlib
+    win32:LIBS += -llibpng16 -lzlib
     win32:QMAKE_LIBDIR+="../../lpng/projects/vstudio/Release Library"
 # Unix
-    unix:LIBS += -lpng -zlib
-    unix:QMAKE_LIBDIR += /usr/local/lib /usr/lib/x86_64-linux-gnu/
+    #unix:LIBS += -lpng -zlib
+    #unix:QMAKE_LIBDIR += /usr/local/lib /usr/lib/x86_64-linux-gnu/
 }
diff --git a/frontend_qt/howto_build_qzint_using_msvs2015.txt b/frontend_qt/howto_build_qzint_using_msvs2015.txt
index 07c1a1a8..a53c9c34 100644
--- a/frontend_qt/howto_build_qzint_using_msvs2015.txt
+++ b/frontend_qt/howto_build_qzint_using_msvs2015.txt
@@ -18,6 +18,7 @@ Folder structure:
 
 Build libpng:
 Open $ZH\..\lpng\projects\vstudio with VS2015 gui and convert the project
+Set Project settings->C++->Code Generation->Library: Multi-Threadded DLL /MD
 Copy the zlib source as required by the make file (in my case: zlib-1.2.8)
 Build targets "Release Library" for zlib and libpng.