diff --git a/source/QZXing.pri b/source/QZXing.pri
index 0123430..7a624f2 100644
--- a/source/QZXing.pri
+++ b/source/QZXing.pri
@@ -1,7 +1,7 @@
 QT       += core gui
 
-greaterThan(QT_VERSION, 4.7): QT += declarative
-greaterThan(QT_VERSION, 5.0): QT += quick
+greaterThan(QT_VERSION, 4.7): lessThan(QT_VERSION, 5.0): QT += declarative
+greaterThan(QT_MAJOR_VERSION, 4): QT += quick
 
 DEFINES += QZXING_LIBRARY \
         ZXING_ICONV_CONST \
@@ -283,3 +283,7 @@ win32-g++{
 
     SOURCES += $$PWD/zxing/win32/zxing/win_iconv.c
 }
+
+!win32{
+    DEFINES += NO_ICONV
+}
diff --git a/source/qzxing.cpp b/source/qzxing.cpp
index c5cd088..2ac89fd 100644
--- a/source/qzxing.cpp
+++ b/source/qzxing.cpp
@@ -180,7 +180,6 @@ QString QZXing::decodeImage(QImage &image, int maxWidth, int maxHeight, bool smo
 
     if(image.isNull())
     {
-        qDebug() << "Image is Null";
         emit decodingFinished(false);
         processingTime = t.elapsed();
         return "";