diff --git a/src/makefile.am b/src/makefile.am
index 1095cfe..ecf892c 100644
--- a/src/makefile.am
+++ b/src/makefile.am
@@ -42,7 +42,7 @@ rebuild-ts: ${LANG_TS}
 	${RCC} -o $@ $<
 
 moc_%.cxx: %.hxx
-	${MOC} -DMOC ${CPPFLAGS} -o $@ $<
+	${MOC} -DMOC ${CPPFLAGS} ${CXXFLAGS} -o $@ $<
 
 ui_%.hxx: %.ui
 	${UIC} -o $@ $<