diff --git a/src/src.pro b/src/src.pro
index d14709c2d..7066b7a73 100644
--- a/src/src.pro
+++ b/src/src.pro
@@ -30,7 +30,7 @@ PKGCONFIG += libtorrent
 QT += xml network
 
 contains(DEBUG_MODE, 0){
-  eval(QT_VERSION = 4.2.0) {
+  contains(QT_VERSION, 4.2.0) {
     message(Qt 4.2.0 detected : enabling debug output because of a bug in this version of Qt)
   }else{
     DEFINES += QT_NO_DEBUG_OUTPUT