diff --git a/__init__.py b/__init__.py
index 6be6e79..ce7599a 100644
--- a/__init__.py
+++ b/__init__.py
@@ -43,7 +43,7 @@
 import SCons.Tool
 import SCons.Util
 
-class ToolQt5Warning(SCons.Warnings.Warning):
+class ToolQt5Warning(SCons.Warnings.SConsWarning):
     pass
 
 class GeneratedMocFileNotIncluded(ToolQt5Warning):
@@ -771,7 +771,7 @@ def locateQt5Command(env, command, qtdir) :
         QT5_QRCCXXPREFIX = 'qrc_',
         QT5_MOCDEFPREFIX = '-D',
         QT5_MOCDEFSUFFIX = '',
-        QT5_MOCDEFINES = '${_defines(QT5_MOCDEFPREFIX, CPPDEFINES, QT5_MOCDEFSUFFIX, __env__)}',
+        QT5_MOCDEFINES = '${_defines(QT5_MOCDEFPREFIX, CPPDEFINES, QT5_MOCDEFSUFFIX, __env__, TARGET, SOURCE)}',
         QT5_MOCCPPPATH = [],
         QT5_MOCINCFLAGS = '$( ${_concat(QT5_MOCINCPREFIX, QT5_MOCCPPPATH, INCSUFFIX, __env__, RDirs)} $)',