--- a/tests/test.py	Sat Mar 05 14:31:30 2022 +0100
+++ b/tests/test.py	Sat Mar 05 15:26:21 2022 +0100
@@ -2014,7 +2014,7 @@
         self.assertEqual(u"1010", x)
         # caching should have no effect
         y = getattr(cfg, self.interpolate_meth)(u"{{intl.cache.items|Empty}}{{intl.cache.items}}")
-        self.assertEqual(u"1010", y)        
+        self.assertEqual(u"1010", y)
 
     def test_interpolate_wrong_syntax(self):
         cfg = configmix.load()
@@ -2048,6 +2048,88 @@
         y = getattr(cfg, self.interpolate_meth)(u"no-interpolation-here")
         self.assertEqual(u"no-interpolation-here", y)
 
+    def test_single_load_removes_DEL_VALUE(self):
+        cfg = configmix.load(os.path.join(TESTDATADIR, "conf20.yml"))
+        self.assertRaises(
+            KeyError,
+            cfg.getvar,
+            u("not-deleted"))
+
+    def test_single_safeload_removes_DEL_VALUE(self):
+        cfg = configmix.safe_load(os.path.join(TESTDATADIR, "conf20.yml"))
+        self.assertRaises(
+            KeyError,
+            cfg.getvar,
+            u("not-deleted"))
+
+    def test_never_expanding_lone_DEL_VALUE(self):
+        cfg = {
+            u("key1"): u("{{::DEL::}}"),
+            u("subkey2"): {
+                u("key3"): u("{{::DEL::}}")
+            }
+        }
+        cfg = configmix.config.Configuration(cfg)
+        print(repr(cfg))
+        self.assertEqual(u("{{::DEL::}}"), cfg.getvar_s(u("key1")))
+        self.assertEqual(u("{{::DEL::}}"), cfg.getvar_s(u("subkey2.key3")))
+
+    def test_merge_does_never_expand(self):
+        cfg1 = configmix.load(os.path.join(TESTDATADIR, "conf20.yml"))
+        self.assertEqual(u("{{appdir}}/locale"), cfg1.getvar(u("intl.localedir")))
+        self.assertRaises(
+            KeyError,
+            cfg1.getvar_s,
+            u("intl.localedir"))
+
+        cfg2 = {
+            u("process"): u("{{::DEL::}}"),
+            u("intl"): {
+                u("localedir"): u("{{appdir}}/other-locale"),
+                u("cache"): u("{{::DEL::}}")
+            }
+        }
+        cfg = configmix.merge(configmix.config.Configuration(cfg2), cfg1)
+        self.assertEqual(
+            u("{{appdir}}/other-locale"),
+            cfg.getvar(u("intl.localedir")))
+        self.assertRaises(
+            KeyError,
+            cfg.getvar,
+            u("process"))
+        self.assertRaises(
+            KeyError,
+            cfg.getvar,
+            u("intl.cache"))
+
+    def test_safemerge_does_never_expand(self):
+        cfg1 = configmix.safe_load(os.path.join(TESTDATADIR, "conf20.yml"))
+        self.assertEqual(u("{{appdir}}/locale"), cfg1.getvar(u("intl.localedir")))
+        self.assertRaises(
+            KeyError,
+            cfg1.getvar_s,
+            u("intl.localedir"))
+
+        cfg2 = {
+            u("process"): u("{{::DEL::}}"),
+            u("intl"): {
+                u("localedir"): u("{{appdir}}/other-locale"),
+                u("cache"): u("{{::DEL::}}")
+            }
+        }
+        cfg = configmix.safe_merge(configmix.config.Configuration(cfg2), cfg1)
+        self.assertEqual(
+            u("{{appdir}}/other-locale"),
+            cfg.getvar(u("intl.localedir")))
+        self.assertRaises(
+            KeyError,
+            cfg.getvar,
+            u("process"))
+        self.assertRaises(
+            KeyError,
+            cfg.getvar,
+            u("intl.cache"))
+
 
 class T09Parser(_TParserMixin, unittest.TestCase):