diff --git a/app/src/Controller/MatchgridRecordsController.php b/app/src/Controller/MatchgridRecordsController.php
index 7d92bd1c4..7a5734cfe 100644
--- a/app/src/Controller/MatchgridRecordsController.php
+++ b/app/src/Controller/MatchgridRecordsController.php
@@ -202,6 +202,16 @@ public function edit($id) {
           throw new \InvalidArgumentException(__('match.er.records.sorid'));
         }
         
+        if($sorid != $obj->sorid) {
+          // As a sanity check, we don't permit the SORID to be changed, since
+          // MatchService does not behave consistently at the moment. (Upsert
+          // can't tell the row changed since we don't pass it the row ID, so it
+          // may create a duplicate row.) This should ultimately get fixed as
+          // part of CO-2138.
+          
+          throw new \InvalidArgumentException(__('match.er.records.sorid.diff'));
+        }
+        
         unset($reqData['sor']);
         unset($reqData['sorid']);
         unset($reqData['matchgrid_id']);
@@ -212,9 +222,8 @@ public function edit($id) {
         $MatchService->setConfig($this->cur_mg->id);
         
         // Unlike add (which verifies no entries for sor+sorid), we don't sanity
-        // check on edit. Basically, we assume the Matchgrid Admin knows what they're
-        // doing, and if they have a use case for changing the SOR of a matchgrid
-        // entry, then let them do it.
+        // check on edit. Basically, we assume the Matchgrid Admin knows what
+        // they're doing.
         
         // Instantiate the AttributeManager
         $AttributeManager = new AttributeManager();
diff --git a/app/src/Locale/en_US/default.po b/app/src/Locale/en_US/default.po
index aab03d0fe..c6efc1771 100644
--- a/app/src/Locale/en_US/default.po
+++ b/app/src/Locale/en_US/default.po
@@ -276,6 +276,9 @@ msgstr "Match Request {0} already exists for this System of Record ID"
 msgid "match.er.records.sorid"
 msgstr "A System of Record ID is required"
 
+msgid "match.er.records.sorid.diff"
+msgstr "Changing the System of Record ID is not supported"
+
 msgid "match.er.rules.unsuccessful"
 msgstr "No rules successfully completed"