diff --git a/tests/face/ethernet-address.cpp b/tests/face/ethernet-address.cpp
index 02f6918..92626b2 100644
--- a/tests/face/ethernet-address.cpp
+++ b/tests/face/ethernet-address.cpp
@@ -39,13 +39,13 @@
 
 BOOST_AUTO_TEST_CASE(ToString)
 {
-  BOOST_CHECK_EQUAL(ethernet::Address().toString(),
+  BOOST_CHECK_EQUAL(ethernet::Address().toString('-'),
                     "00-00-00-00-00-00");
-  BOOST_CHECK_EQUAL(ethernet::getBroadcastAddress().toString(':'),
+  BOOST_CHECK_EQUAL(ethernet::getBroadcastAddress().toString(),
                     "ff:ff:ff:ff:ff:ff");
-  BOOST_CHECK_EQUAL(ethernet::Address(0x01, 0x23, 0x45, 0x67, 0x89, 0xAB).toString(),
+  BOOST_CHECK_EQUAL(ethernet::Address(0x01, 0x23, 0x45, 0x67, 0x89, 0xAB).toString('-'),
                     "01-23-45-67-89-ab");
-  BOOST_CHECK_EQUAL(ethernet::Address(0x01, 0x23, 0x45, 0x67, 0x89, 0xAB).toString(':'),
+  BOOST_CHECK_EQUAL(ethernet::Address(0x01, 0x23, 0x45, 0x67, 0x89, 0xAB).toString(),
                     "01:23:45:67:89:ab");
 }
 
diff --git a/tests/face/ethernet.cpp b/tests/face/ethernet.cpp
index 706a697..d27fda4 100644
--- a/tests/face/ethernet.cpp
+++ b/tests/face/ethernet.cpp
@@ -118,7 +118,7 @@
   BOOST_CHECK(!face->isOnDemand());
   BOOST_CHECK_EQUAL(face->isLocal(), false);
   BOOST_CHECK_EQUAL(face->getRemoteUri().toString(),
-                    "ether://" + ethernet::getDefaultMulticastAddress().toString(':'));
+                    "ether://" + ethernet::getDefaultMulticastAddress().toString());
   BOOST_CHECK_EQUAL(face->getLocalUri().toString(),
                     "dev://" + m_interfaces.front()->name);