diff --git a/src/Model/Migration/Definitions.hs b/src/Model/Migration/Definitions.hs
index 8e458ac47..b41b8f61b 100644
--- a/src/Model/Migration/Definitions.hs
+++ b/src/Model/Migration/Definitions.hs
@@ -80,7 +80,7 @@ migrateManual = do
     , ("user_lower_ident",                    "CREATE INDEX user_lower_ident ON \"user\" (lower(ident))"                                 )
     , ("submission_sheet",                    "CREATE INDEX submission_sheet ON submission (sheet)"                                      )
     , ("submission_edit_submission",          "CREATE INDEX submission_edit_submission ON submission_edit (submission)"                  )
-    , ("user_ldap_primary_key",               "CREATE INDEX user_ldap_primary_key ON \"user\" (ldap_primary_key)"                        )
+--  , ("user_ldap_primary_key",               "CREATE INDEX user_ldap_primary_key ON \"user\" (ldap_primary_key)"                        ) -- TODO: reintroduce
     , ("file_content_entry_chunk_hash",       "CREATE INDEX file_content_entry_chunk_hash ON \"file_content_entry\" (chunk_hash)"        )
     , ("sent_mail_bounce_secret",             "CREATE INDEX sent_mail_bounce_secret ON \"sent_mail\" (bounce_secret) WHERE bounce_secret IS NOT NULL")
     , ("sent_mail_recipient",                 "CREATE INDEX sent_mail_recipient ON \"sent_mail\" (recipient) WHERE recipient IS NOT NULL")