diff --git a/site_ansto/instrument/util/config_edit.py b/site_ansto/instrument/util/config_edit.py
index d57c4b66..1d978748 100755
--- a/site_ansto/instrument/util/config_edit.py
+++ b/site_ansto/instrument/util/config_edit.py
@@ -443,7 +443,7 @@ class InstConfigManager:
         self.opt_lb.set_focus(0)
         return
 
-    def __imp_unavailable(self, imp):
+    def __imp_unavailable(self, opt, imp):
         """Return True if an implementation is unavailable because it is used
         by an enabled option.
         """
@@ -453,6 +453,10 @@ class InstConfigManager:
         ckopt = self.cf_dat.imp2opt_dict[imp]
         if ckopt == 'none':
             return False
+
+        opt_imp = self.cf_dat.opt_dict[opt]['selected_imp']
+        if opt_imp == imp:
+            return False
         elif self.cf_dat.opt_dict[ckopt]['enabled']:
             return True
         else:
@@ -462,7 +466,7 @@ class InstConfigManager:
         """Generate the appropriate listwalker for the given option."""
         imp_items = []
         for imp in self.cf_dat.iter_implementations(opt):
-            if self.__imp_unavailable(imp):
+            if self.__imp_unavailable(opt, imp):
                 continue
             if imp == self.cf_dat.opt_dict[opt]['selected_imp']:
                 imp_items.append((imp, True))
@@ -509,7 +513,7 @@ class InstConfigManager:
         opt = button.get_label().split(':')[0]
         imp = self.cf_dat.opt_dict[opt]['selected_imp']
         if new_state == True:
-            if self.__imp_unavailable(imp):
+            if self.__imp_unavailable(opt, imp):
                 self.cf_dat.opt_dict[opt]['selected_imp'] = 'none'
                 imp_none_button = self.imp_lw.button_dict['none']
                 imp_none_button.set_state(True)
@@ -526,8 +530,8 @@ class InstConfigManager:
         """Update label on the configuration option when it's implementation is
         changed.
         """
+        imp = button.get_label()
         if new_state == True:
-            imp = button.get_label()
             self.cf_dat.set_imp(opt, imp)
             opt_button = self.opt_lw.button_dict[opt]
             opt_button.set_label('{0}:{1}'.format(opt, imp))