diff --git a/macosx.properties b/macosx.properties
index 1b5744a2..0b062e2e 100644
--- a/macosx.properties
+++ b/macosx.properties
@@ -5,3 +5,13 @@
 # those defined in default.properties, but may be overridden by
 # properties defined in a machine-specific build.properties file.
 #
+
+#
+# Location of the PKCS#11 configuration file for OpenSC on Mac OS X.
+#
+sign.uk.pkcs11Config = ${basedir}/mdx/uk/opensc-mac.cfg
+
+#
+# Signing key alias within the keystore.
+#
+sign.uk.keyAlias = key10