diff --git a/development/scons/SConstruct b/development/scons/SConstruct
index 668859d1ed..467b1832c9 100644
--- a/development/scons/SConstruct
+++ b/development/scons/SConstruct
@@ -1511,8 +1511,6 @@ support = frontend_env.StaticLibrary(
     CCFLAGS =  [
         '$CCFLAGS',
         '-DHAVE_CONFIG_H',
-        '-DQT_CLEAN_NAMESPACE',
-        '-DQT_GENUINE_STR',
         '-DQT_NO_STL',
         '-DQT_NO_KEYWORDS',
     ],
@@ -1592,8 +1590,6 @@ qt4 = frontend_env.StaticLibrary(
     CCFLAGS =  [
         '$CCFLAGS',
         '-DHAVE_CONFIG_H',
-        '-DQT_CLEAN_NAMESPACE',
-        '-DQT_GENUINE_STR',
         '-DQT_NO_STL',
         '-DQT_NO_KEYWORDS',
     ]