diff --git a/app/models/topic_embed.rb b/app/models/topic_embed.rb
index fa8008703..823ce5484 100644
--- a/app/models/topic_embed.rb
+++ b/app/models/topic_embed.rb
@@ -4,6 +4,7 @@ class TopicEmbed < ActiveRecord::Base
   belongs_to :topic
   belongs_to :post
   validates_presence_of :embed_url
+  validates_uniqueness_of :embed_url
 
   def self.normalize_url(url)
     url.downcase.sub(/\/$/, '').sub(/\-+/, '-').strip
diff --git a/lib/post_creator.rb b/lib/post_creator.rb
index bb9723a95..8629d1e87 100644
--- a/lib/post_creator.rb
+++ b/lib/post_creator.rb
@@ -193,7 +193,8 @@ class PostCreator
   # discourse post.
   def create_embedded_topic
     return unless @opts[:embed_url].present?
-    TopicEmbed.create!(topic_id: @post.topic_id, post_id: @post.id, embed_url: @opts[:embed_url])
+    embed = TopicEmbed.new(topic_id: @post.topic_id, post_id: @post.id, embed_url: @opts[:embed_url])
+    rollback_from_errors!(embed) unless embed.save
   end
 
   def handle_spam
diff --git a/spec/components/post_creator_spec.rb b/spec/components/post_creator_spec.rb
index 411e8d715..6a5feef97 100644
--- a/spec/components/post_creator_spec.rb
+++ b/spec/components/post_creator_spec.rb
@@ -559,7 +559,17 @@ describe PostCreator do
                                 title: 'Reviews of Science Ovens',
                                 raw: 'Did you know that you can use microwaves to cook your dinner? Science!')
       creator.create
+      expect(creator.errors).to be_blank
       expect(TopicEmbed.where(embed_url: embed_url).exists?).to eq(true)
+
+      # If we try to create another topic with the embed url, should fail
+      creator = PostCreator.new(user,
+                                embed_url: embed_url,
+                                title: 'More Reviews of Science Ovens',
+                                raw: 'As if anyone ever wanted to learn more about them!')
+      result = creator.create
+      expect(result).to be_present
+      expect(creator.errors).to be_present
     end
   end