diff --git a/src/libbitdht.pro b/src/libbitdht.pro
index e36b05d..0c3a1d6 100644
--- a/src/libbitdht.pro
+++ b/src/libbitdht.pro
@@ -59,11 +59,15 @@ win32 {
 		#DEFINES *= WINDOWS_SYS WIN32 STATICLIB MINGW
 		DESTDIR = lib
 
-		# Switch off optimization
+		# Switch off optimization for release version
 		QMAKE_CXXFLAGS_RELEASE -= -O2
 		QMAKE_CXXFLAGS_RELEASE += -O0
 		QMAKE_CFLAGS_RELEASE -= -O2
 		QMAKE_CFLAGS_RELEASE += -O0
+
+		# Switch on optimization for debug version
+		#QMAKE_CXXFLAGS_DEBUG += -O2
+		#QMAKE_CFLAGS_DEBUG += -O2
 }
 
 ################################# MacOSX ##########################################