diff --git a/app/assets/javascripts/discourse/controllers/composer.js.es6 b/app/assets/javascripts/discourse/controllers/composer.js.es6
index d08f59c9f4b..df41d58a0a9 100644
--- a/app/assets/javascripts/discourse/controllers/composer.js.es6
+++ b/app/assets/javascripts/discourse/controllers/composer.js.es6
@@ -696,7 +696,12 @@ export default Ember.Controller.extend({
     }
 
     if (opts.topicTags && !this.site.mobileView && this.site.get('can_tag_topics')) {
-      this.set('model.tags', opts.topicTags.split(","));
+      const self = this;
+      let tags = escapeExpression(opts.topicTags).split(",").slice(0, self.siteSettings.max_tags_per_topic);
+      tags.forEach(function(tag, index, array) {
+        array[index] = tag.substring(0, self.siteSettings.max_tag_length);
+      });
+      self.set('model.tags', tags);
     }
 
     if (opts.topicBody) {