diff --git a/src/osd/sdl/sdl.mak b/src/osd/sdl/sdl.mak
index 760b66f9f7e..e0dcfdce356 100644
--- a/src/osd/sdl/sdl.mak
+++ b/src/osd/sdl/sdl.mak
@@ -728,7 +728,7 @@ endif # OS2
 
 ifndef NO_USE_QTDEBUG
 $(OSDOBJ)/%.moc.c: $(OSDSRC)/%.h
-	$(MOC) $(MOCINCPATH) $(DEFS) $< -o $@
+	$(MOC) $(MOCINCPATH) $< -o $@
 
 DEBUGOBJS = \
 	$(OSDOBJ)/modules/debugger/qt/debuggerview.o \
diff --git a/src/osd/windows/windows.mak b/src/osd/windows/windows.mak
index a4285a2a410..b9cc10886cb 100644
--- a/src/osd/windows/windows.mak
+++ b/src/osd/windows/windows.mak
@@ -432,7 +432,7 @@ INCPATH += -I$(QT_INSTALL_HEADERS)/QtCore -I$(QT_INSTALL_HEADERS)/QtGui -I$(QT_I
 
 MOC = @moc
 $(OSDOBJ)/%.moc.c: $(OSDSRC)/%.h
-	$(MOC) $(INCPATH) $(DEFS) $< -o $@
+	$(MOC) $(INCPATH) $< -o $@
 
 OSDOBJS += \
 	$(OSDOBJ)/modules/debugger/qt/debugqtview.o \