Index: django/db/models/fields/related.py
===================================================================
--- django/db/models/fields/related.py	(revision 3841)
+++ django/db/models/fields/related.py	(working copy)
@@ -618,7 +618,7 @@
             msg = gettext_lazy('Separate multiple IDs with commas.')
         else:
             msg = gettext_lazy('Hold down "Control", or "Command" on a Mac, to select more than one.')
-        self.help_text = string_concat(self.help_text, msg)
+        self.help_text = string_concat(self.help_text, " ", msg)
 
     def get_manipulator_field_objs(self):
         if self.rel.raw_id_admin: