diff --git a/src/libs/cplusplus/cplusplus.pro b/src/libs/cplusplus/cplusplus.pro
index 4c272c5a6f2..5051814dbfd 100644
--- a/src/libs/cplusplus/cplusplus.pro
+++ b/src/libs/cplusplus/cplusplus.pro
@@ -4,6 +4,7 @@ TARGET = CPlusPlus
 DEFINES += NDEBUG
 #DEFINES += DEBUG_LOOKUP
 unix:QMAKE_CXXFLAGS_DEBUG += -O2
+win32:QMAKE_CXXFLAGS_DEBUG += -O2
 
 include(../../qtcreatorlibrary.pri)
 include(cplusplus-lib.pri)