diff --git a/app/soapbox/features/scheduled_statuses/builder.js b/app/soapbox/features/scheduled_statuses/builder.js
index 6b3d1a4f8..8e3417582 100644
--- a/app/soapbox/features/scheduled_statuses/builder.js
+++ b/app/soapbox/features/scheduled_statuses/builder.js
@@ -1,4 +1,4 @@
-import { fromJS } from 'immutable';
+import { Map as ImmutableMap } from 'immutable';
 
 import { normalizeStatus } from 'soapbox/normalizers/status';
 import { calculateStatus } from 'soapbox/reducers/statuses';
@@ -11,7 +11,7 @@ export const buildStatus = (state, scheduledStatus) => {
   const params = scheduledStatus.get('params');
   const account = getAccount(state, me);
 
-  const status = {
+  const status = ImmutableMap({
     account,
     content: params.get('text', '').replace(new RegExp('\n', 'g'), '<br>'), /* eslint-disable-line no-control-regex */
     created_at: params.get('scheduled_at'),
@@ -23,7 +23,7 @@ export const buildStatus = (state, scheduledStatus) => {
     uri: `/scheduled_statuses/${scheduledStatus.get('id')}`,
     url: `/scheduled_statuses/${scheduledStatus.get('id')}`,
     visibility: params.get('visibility'),
-  };
+  });
 
-  return calculateStatus(normalizeStatus(fromJS(status)));
+  return calculateStatus(normalizeStatus(status));
 };
diff --git a/app/soapbox/features/ui/util/pending_status_builder.js b/app/soapbox/features/ui/util/pending_status_builder.js
index 374d79c64..b51b1ceed 100644
--- a/app/soapbox/features/ui/util/pending_status_builder.js
+++ b/app/soapbox/features/ui/util/pending_status_builder.js
@@ -1,4 +1,4 @@
-import { Map as ImmutableMap, List as ImmutableList, fromJS } from 'immutable';
+import { Map as ImmutableMap, List as ImmutableList } from 'immutable';
 
 import { normalizeStatus } from 'soapbox/normalizers/status';
 import { calculateStatus } from 'soapbox/reducers/statuses';
@@ -6,11 +6,11 @@ import { makeGetAccount } from 'soapbox/selectors';
 
 const getAccount = makeGetAccount();
 
-const getMentions = pendingStatus => {
+const buildMentions = pendingStatus => {
   if (pendingStatus.get('in_reply_to_id')) {
-    return ImmutableList(pendingStatus.get('to') || []).map(mention => ImmutableMap({
-      username: mention.split('@')[0],
-      acct: mention,
+    return ImmutableList(pendingStatus.get('to') || []).map(acct => ImmutableMap({
+      acct,
+      username: acct.split('@')[0],
     }));
   } else {
     return ImmutableList();
@@ -22,19 +22,19 @@ export const buildStatus = (state, pendingStatus, idempotencyKey) => {
   const account = getAccount(state, me);
   const inReplyToId = pendingStatus.get('in_reply_to_id');
 
-  const status = {
+  const status = ImmutableMap({
     account,
     content: pendingStatus.get('status', '').replace(new RegExp('\n', 'g'), '<br>'), /* eslint-disable-line no-control-regex */
     id: `末pending-${idempotencyKey}`,
     in_reply_to_account_id: state.getIn(['statuses', inReplyToId, 'account'], null),
     in_reply_to_id: inReplyToId,
     media_attachments: pendingStatus.get('media_ids', ImmutableList()).map(id => ImmutableMap({ id })),
-    mentions: getMentions(pendingStatus),
+    mentions: buildMentions(pendingStatus),
     poll: pendingStatus.get('poll', null),
     quote: pendingStatus.get('quote_id', null),
     sensitive: pendingStatus.get('sensitive', false),
     visibility: pendingStatus.get('visibility', 'public'),
-  };
+  });
 
-  return calculateStatus(normalizeStatus(fromJS(status)));
+  return calculateStatus(normalizeStatus(status));
 };
diff --git a/app/soapbox/normalizers/status.js b/app/soapbox/normalizers/status.js
index 288a07498..8377a1a51 100644
--- a/app/soapbox/normalizers/status.js
+++ b/app/soapbox/normalizers/status.js
@@ -28,8 +28,10 @@ const baseStatus = ImmutableMap({
   visibility: 'public',
 });
 
+// Merger function for only overriding undefined values
 const mergeDefined = (oldVal, newVal) => oldVal === undefined ? newVal : oldVal;
 
+// Merge base status
 const setRequiredFields = status => {
   return status.mergeDeepWith(mergeDefined, baseStatus);
 };
@@ -49,7 +51,7 @@ const normalizeAttachment = attachment => {
     remote_url: url,
   });
 
-  return attachment.mergeWith((o, n) => o || n, base);
+  return attachment.mergeWith(mergeDefined, base);
 };
 
 const normalizeAttachments = status => {
@@ -58,9 +60,26 @@ const normalizeAttachments = status => {
   });
 };
 
+// Normalize mentions
+const normalizeMention = mention => {
+  const base = ImmutableMap({
+    acct: '',
+    username: (mention.get('acct') || '').split('@')[0],
+    url: '',
+  });
+
+  return mention.mergeWith(mergeDefined, base);
+};
+
+const normalizeMentions = status => {
+  return status.update('mentions', ImmutableList(), mentions => {
+    return mentions.map(normalizeMention);
+  });
+};
+
 // Fix order of mentions
-const fixMentions = status => {
-  const mentions = status.get('mentions');
+const fixMentionsOrder = status => {
+  const mentions = status.get('mentions', ImmutableList());
   const inReplyToAccountId = status.get('in_reply_to_account_id');
 
   // Sort the replied-to mention to the top
@@ -103,9 +122,10 @@ const fixQuote = status => {
 export const normalizeStatus = status => {
   return status.withMutations(status => {
     setRequiredFields(status);
-    fixMentions(status);
-    fixQuote(status);
-    addSelfMention(status);
     normalizeAttachments(status);
+    normalizeMentions(status);
+    fixMentionsOrder(status);
+    addSelfMention(status);
+    fixQuote(status);
   });
 };