diff --git a/APPL/API2/model_issues.inc b/APPL/API2/model_issues.inc
index 68a56edffb..5cb8a560db 100644
--- a/APPL/API2/model_issues.inc
+++ b/APPL/API2/model_issues.inc
@@ -57,8 +57,9 @@ function model_issues(mld_key, params)
              "building"   : { dbs: "alg_v_allonroerendgoed.alg_gebouw_key",        typ: "key",      foreign: "alg_gebouw",                 label: L("lcl_building"),          track: true,  filter: "exact" },
              "floor"      : { dbs: "alg_v_allonroerendgoed.alg_verdieping_key",    typ: "key",      foreign: "alg_verdieping",             label: L("lcl_floor"),             track: true,  filter: "exact" },
              "room"       : { dbs: "alg_v_allonroerendgoed.alg_ruimte_key",        typ: "key",      foreign: "alg_ruimte",                 label: L("lcl_room"),              track: true,  filter: "exact" },
-             "terrain"    : { dbs: "alg_v_allonroerendgoed.alg_terreinsector_key", typ: "key",      foreign: "alg_terreinsector",          label: L("lcl_room"),            track: true,  filter: "exact" },
-             "parent"     : { dbs: "mld_melding_parentkey",                        typ: "key",      xforeign: "mld_melding",                label: L("lcl_mld_completion_in"),              track: true,  filter: "exact" },
+             "terrain"    : { dbs: "alg_v_allonroerendgoed.alg_terreinsector_key", typ: "key",      foreign: "alg_terreinsector",          label: L("lcl_room"),              track: true,  filter: "exact" },
+             "parent"     : { dbs: "mld_melding_parentkey",                        typ: "key",      xforeign: "mld_melding",               label: L("lcl_mld_completion_in"), track: true,  filter: "exact" },
+             "extern_id"  : { dbs: "mld_melding_externnr",                         typ: "varchar",                                         label: L("lcl_mld_externr"),       track: true,  filter: "exact" },
              "xstatus"    : { dbs: "mld_melding_status",
                               val: fnextendedStatus,                               typ: "key",      foreign: mld.getmldstatustext,         label: L("lcl_extended_status"), track: true,  filter: "exact", readonly: true }
             };