diff --git a/testing/tests/regression-suite/0852-freebusy-no-user.result b/testing/tests/regression-suite/0852-freebusy-no-user.result
new file mode 100644
index 00000000..1c99856f
--- /dev/null
+++ b/testing/tests/regression-suite/0852-freebusy-no-user.result
@@ -0,0 +1,6 @@
+HTTP/1.1 404 Not Found
+Date: Dow, 01 Jan 2000 00:00:00 GMT
+Content-Length: 60
+Content-Type: text/plain; charset="utf-8"
+
+No user found matching user1@non-existant-email-address.com
diff --git a/testing/tests/regression-suite/0852-freebusy-no-user.test b/testing/tests/regression-suite/0852-freebusy-no-user.test
new file mode 100644
index 00000000..d25dcaaa
--- /dev/null
+++ b/testing/tests/regression-suite/0852-freebusy-no-user.test
@@ -0,0 +1,6 @@
+#
+# Request a freebusy report by URL for an invalid email address
+#
+TYPE=GET
+URL=http://regression.host/freebusy.php/user1@non-existant-email-address.com
+HEAD