diff --git a/GPy/core/parameterization/parameter_core.py b/GPy/core/parameterization/parameter_core.py
index bee160b2..13c2ee59 100644
--- a/GPy/core/parameterization/parameter_core.py
+++ b/GPy/core/parameterization/parameter_core.py
@@ -947,7 +947,7 @@ class Parameterizable(OptimizationHandlable):
             self._add_parameter_name(param, ignore_added_names)
         # and makes sure to not delete programmatically added parameters
         for other in self.parameters[::-1]:
-            if other is not param and other.name.startswith(param.name):
+            if other is not param and other.name == param.name:
                 warn_and_retry(param, _name_digit.match(other.name))
                 return
         if pname not in dir(self):
@@ -955,6 +955,7 @@ class Parameterizable(OptimizationHandlable):
             self._added_names_.add(pname)
         elif pname in self.__dict__:
             if pname in self._added_names_:
+                print self._added_names_
                 other = self.__dict__[pname]
                 if not (param is other):
                     del self.__dict__[pname]