diff --git a/libbitdht/src/libbitdht.pro b/libbitdht/src/libbitdht.pro
index cb2f3b4b0..cb96208e5 100644
--- a/libbitdht/src/libbitdht.pro
+++ b/libbitdht/src/libbitdht.pro
@@ -66,6 +66,16 @@ win32 {
 		# Switch on extra warnings
 		QMAKE_CFLAGS += -Wextra
 		QMAKE_CXXFLAGS += -Wextra
+
+		# 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 ##########################################
diff --git a/libretroshare/src/libretroshare.pro b/libretroshare/src/libretroshare.pro
index 9383e592f..1d7ac0863 100644
--- a/libretroshare/src/libretroshare.pro
+++ b/libretroshare/src/libretroshare.pro
@@ -275,6 +275,16 @@ win32 {
 	QMAKE_CFLAGS += -Wextra
 	QMAKE_CXXFLAGS += -Wextra
 
+	# 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
+
 	DEFINES += USE_CMD_ARGS
 
 	#miniupnp implementation files
diff --git a/openpgpsdk/src/openpgpsdk.pro b/openpgpsdk/src/openpgpsdk.pro
index 41b84219d..8575b8e21 100644
--- a/openpgpsdk/src/openpgpsdk.pro
+++ b/openpgpsdk/src/openpgpsdk.pro
@@ -17,6 +17,16 @@ linux-* {
 }
 
 win32 {
+	# 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
+
 	SSL_DIR = ../../../openssl-1.0.1c
 	ZLIB_DIR = ../../../zlib-1.2.3
 	BZIP_DIR = ../../../bzip2-1.0.6
diff --git a/plugins/Common/retroshare_plugin.pri b/plugins/Common/retroshare_plugin.pri
index 06385b858..83af5c9c9 100644
--- a/plugins/Common/retroshare_plugin.pri
+++ b/plugins/Common/retroshare_plugin.pri
@@ -23,6 +23,16 @@ win32 {
 	DEFINES += MINIUPNPC_VERSION=13
 #	DESTDIR = lib
 
+	# 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
+
 	DEFINES += USE_CMD_ARGS
 
 	#miniupnp implementation files
diff --git a/retroshare-gui/src/retroshare-gui.pro b/retroshare-gui/src/retroshare-gui.pro
index a5fcc9153..4a6223bd1 100644
--- a/retroshare-gui/src/retroshare-gui.pro
+++ b/retroshare-gui/src/retroshare-gui.pro
@@ -109,6 +109,16 @@ win32 {
 	QMAKE_CFLAGS += -Wextra
 	QMAKE_CXXFLAGS += -Wextra
 
+	# 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
+
 	OBJECTS_DIR = temp/obj
 	#LIBS += -L"D/Qt/2009.03/qt/plugins/imageformats"
 	#QTPLUGIN += qjpeg