=== modified file 'mandos-ctl'
--- mandos-ctl	2019-03-06 22:21:51 +0000
+++ mandos-ctl	2019-03-06 22:56:24 +0000
@@ -1176,6 +1176,10 @@
         self.assert_command_from_args(["--checker", ":", "foo"],
                                       SetCheckerCmd, value_to_set=":")
 
+    def test_checker_empty(self):
+        self.assert_command_from_args(["--checker", "", "foo"],
+                                      SetCheckerCmd, value_to_set="")
+
     def test_timeout(self):
         self.assert_command_from_args(["--timeout", "PT5M", "foo"],
                                       SetTimeoutCmd,