diff --git a/app/models/announcement_reaction.rb b/app/models/announcement_reaction.rb
index 46d9fc290ff..855dfc9e3a6 100644
--- a/app/models/announcement_reaction.rb
+++ b/app/models/announcement_reaction.rb
@@ -14,7 +14,7 @@
 #
 
 class AnnouncementReaction < ApplicationRecord
-  before_validation :set_custom_emoji
+  before_validation :set_custom_emoji, if: :name?
   after_commit :queue_publish
 
   belongs_to :account
@@ -27,7 +27,7 @@ class AnnouncementReaction < ApplicationRecord
   private
 
   def set_custom_emoji
-    self.custom_emoji = CustomEmoji.local.enabled.find_by(shortcode: name) if name.present?
+    self.custom_emoji = CustomEmoji.local.enabled.find_by(shortcode: name)
   end
 
   def queue_publish
diff --git a/spec/models/announcement_reaction_spec.rb b/spec/models/announcement_reaction_spec.rb
new file mode 100644
index 00000000000..e02a8dcd069
--- /dev/null
+++ b/spec/models/announcement_reaction_spec.rb
@@ -0,0 +1,63 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+RSpec.describe AnnouncementReaction do
+  describe 'Associations' do
+    it { is_expected.to belong_to(:account) }
+    it { is_expected.to belong_to(:announcement).inverse_of(:announcement_reactions) }
+    it { is_expected.to belong_to(:custom_emoji).optional }
+  end
+
+  describe 'Validations' do
+    subject { Fabricate.build :announcement_reaction }
+
+    it { is_expected.to validate_presence_of(:name) }
+    it { is_expected.to allow_values('😀').for(:name) }
+    it { is_expected.to_not allow_values('INVALID').for(:name) }
+
+    context 'when reaction limit is reached' do
+      subject { Fabricate.build :announcement_reaction, announcement: announcement_reaction.announcement }
+
+      let(:announcement_reaction) { Fabricate :announcement_reaction, name: '😊' }
+
+      before { stub_const 'ReactionValidator::LIMIT', 1 }
+
+      it { is_expected.to_not allow_values('😀').for(:name).against(:base) }
+    end
+  end
+
+  describe 'Callbacks' do
+    describe 'Setting custom emoji association' do
+      subject { Fabricate.build :announcement_reaction, name: }
+
+      context 'when name is missing' do
+        let(:name) { '' }
+
+        it 'does not set association' do
+          expect { subject.valid? }
+            .to not_change(subject, :custom_emoji).from(be_blank)
+        end
+      end
+
+      context 'when name matches a custom emoji shortcode' do
+        let(:name) { 'custom' }
+        let!(:custom_emoji) { Fabricate :custom_emoji, shortcode: 'custom' }
+
+        it 'sets association' do
+          expect { subject.valid? }
+            .to change(subject, :custom_emoji).from(be_blank).to(custom_emoji)
+        end
+      end
+
+      context 'when name does not match a custom emoji' do
+        let(:name) { 'custom' }
+
+        it 'does not set association' do
+          expect { subject.valid? }
+            .to not_change(subject, :custom_emoji).from(be_blank)
+        end
+      end
+    end
+  end
+end