diff --git a/lib/tests/fixtures/messageinbound/SAMPLE b/lib/tests/fixtures/messageinbound/SAMPLE
index b3231346f9c..26f36eac0c6 100644
--- a/lib/tests/fixtures/messageinbound/SAMPLE
+++ b/lib/tests/fixtures/messageinbound/SAMPLE
@@ -1,3 +1,4 @@
+----CLIENT----
 ----EXPECTEDPLAIN----
 ----EXPECTEDHTML----
 ----FULLSOURCE----
diff --git a/lib/tests/fixtures/messageinbound/evolution.test b/lib/tests/fixtures/messageinbound/evolution.test
index a4dcd24f459..7b8e5ca65c0 100644
--- a/lib/tests/fixtures/messageinbound/evolution.test
+++ b/lib/tests/fixtures/messageinbound/evolution.test
@@ -1,3 +1,9 @@
+----CLIENT----
+OS: Ubuntu 14.04
+Mail Client: Evolution
+Client Version: 31.6.0
+Date: 30/04/2015
+
 ----EXPECTEDPLAIN----
 An ion meets his atom friend on the street and says he's lost an
 electron. "Are you sure?" asks the atom. The ion replies, "I'm
diff --git a/lib/tests/messageinbound_test.php b/lib/tests/messageinbound_test.php
index 7f2ffda3056..52bb2a60133 100644
--- a/lib/tests/messageinbound_test.php
+++ b/lib/tests/messageinbound_test.php
@@ -110,6 +110,7 @@ class core_messageinbound_testcase extends advanced_testcase {
             'FULLSOURCE'        => true,
             'EXPECTEDPLAIN'     => true,
             'EXPECTEDHTML'      => true,
+            'CLIENT'            => true, // Required but not needed for tests, just for documentation.
         );
         $section = null;
         $data = array();