diff --git a/ts/models/messages.ts b/ts/models/messages.ts
index af6ec307bf..77de98cc42 100644
--- a/ts/models/messages.ts
+++ b/ts/models/messages.ts
@@ -334,7 +334,14 @@ export class MessageModel extends window.Backbone.Model<MessageAttributesType> {
     const errors = _.reject(allErrors, error =>
       Boolean(error.identifier || error.number)
     );
-    const errorsGroupedById = _.groupBy(allErrors, 'number');
+    const errorsGroupedById = _.groupBy(allErrors, error => {
+      const identifier = error.identifier || error.number;
+      if (!identifier) {
+        return null;
+      }
+
+      return window.ConversationController.getConversationId(identifier);
+    });
     const finalContacts = (conversationIds || []).map(id => {
       const errorsForContact = errorsGroupedById[id];
       const isOutgoingKeyError = Boolean(
@@ -1703,17 +1710,18 @@ export class MessageModel extends window.Backbone.Model<MessageAttributesType> {
       );
     });
     errors = errors.map(e => {
-      if (
-        e.constructor === Error ||
-        e.constructor === TypeError ||
-        e.constructor === ReferenceError
-      ) {
+      // Note: in our environment, instanceof can be scary, so we have a backup check
+      //   (Node.js vs Browser context).
+      // We check instanceof second because typescript believes that anything that comes
+      //   through here must be an instance of Error, so e is 'never' after that check.
+      if ((e.message && e.stack) || e instanceof Error) {
         return _.pick(
           e,
           'name',
           'message',
           'code',
           'number',
+          'identifier',
           'reason'
         ) as Required<Error>;
       }