diff --git a/src/ifcpatch/Makefile b/src/ifcpatch/Makefile
index 4fa62f5ff0..d01a95b395 100644
--- a/src/ifcpatch/Makefile
+++ b/src/ifcpatch/Makefile
@@ -16,6 +16,12 @@
 # You should have received a copy of the GNU General Public License
 # along with BlenderBIM Add-on.  If not, see <http://www.gnu.org/licenses/>.
 
+VERSION:=`date '+%y%m%d'`
+SED:=sed -i
+ifeq ($(UNAME_S),Darwin)
+SED:=sed -i '' -e
+endif
+
 .PHONY: test
 test:
 	pytest -p no:pytest-blender test
diff --git a/src/ifctester/Makefile b/src/ifctester/Makefile
index 597a8ccb99..7ae89cba16 100644
--- a/src/ifctester/Makefile
+++ b/src/ifctester/Makefile
@@ -1,3 +1,21 @@
+# IfcTester - IDS based model auditing
+# Copyright (C) 2021 Dion Moult <dion@thinkmoult.com>
+#
+# This file is part of IfcTester.
+#
+# IfcTester is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# IfcTester is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with IfcTester.  If not, see <http://www.gnu.org/licenses/>.
+
 VERSION:=`date '+%y%m%d'`
 SED:=sed -i
 ifeq ($(UNAME_S),Darwin)