--- a/configmix/config.py	Fri Dec 17 17:38:17 2021 +0100
+++ b/configmix/config.py	Fri Dec 17 18:58:06 2021 +0100
@@ -579,11 +579,11 @@
         """
         if not path:
             return self
+        eiref = self.expand_if_reference
         try:
-            v = self.expand_if_reference(
-                super(Configuration, self).__getitem__(path[0]))
+            v = eiref(super(Configuration, self).__getitem__(path[0]))
             for p in path[1:]:
-                v = self.expand_if_reference(v[p])
+                v = eiref(v[p])
         except TypeError:
             raise KeyError(
                 "Configuration variable %r not found"
@@ -599,7 +599,7 @@
         """
         return self.expand_ref_uri(key, default=default)
 
-    def expand_if_reference(self, v, default=_MARKER):
+    def expand_if_reference(self, v):
         """Check whether `v` is a configuration reference and -- if true --
         then expand it.
 
@@ -608,13 +608,14 @@
         All non-matching texttypes and all non-texttypes are returned
         unchanged.
 
+        :raise KeyError: If the reverence cannot found
+
         """
         if not isinstance(v, self._TEXTTYPE):
             return v
         if v.startswith(self._STARTTOK_REF) and v.endswith(self._ENDTOK_REF):
             return self.expand_ref_uri(
-                v[len(self._STARTTOK_REF):-len(self._ENDTOK_REF)],
-                default=default)
+                v[len(self._STARTTOK_REF):-len(self._ENDTOK_REF)])
         else:
             return v