diff --git a/app/assets/javascripts/discourse/lib/emoji/emoji.js.erb b/app/assets/javascripts/discourse/lib/emoji/emoji.js.erb
index b15b444cec4..786485e4969 100644
--- a/app/assets/javascripts/discourse/lib/emoji/emoji.js.erb
+++ b/app/assets/javascripts/discourse/lib/emoji/emoji.js.erb
@@ -7,6 +7,7 @@ var emoji = <%= Emoji.standard.map(&:name).flatten.inspect %>;
 
 var extendedEmoji = {};
 Discourse.Dialect.registerEmoji = function(code, url) {
+  code = code.toLowerCase();
   extendedEmoji[code] = url;
 };
 
@@ -53,13 +54,13 @@ var search = function(term, options) {
 Discourse.Emoji.search = search;
 
 var emojiHash = {};
-emoji.forEach(function(code){
-  emojiHash[code] = true;
-});
+emoji.forEach(function(code){ emojiHash[code] = true; });
 
 var urlFor = function(code) {
   var url, set = Discourse.SiteSettings.emoji_set;
 
+  code = code.toLowerCase();
+
   if(extendedEmoji.hasOwnProperty(code)) {
     url = extendedEmoji[code];
   }
@@ -82,10 +83,12 @@ var urlFor = function(code) {
 Discourse.Emoji.urlFor = urlFor;
 
 Discourse.Emoji.exists = function(code){
- return !!(extendedEmoji.hasOwnProperty(code) || emojiHash.hasOwnProperty(code));
+  code = code.toLowerCase();
+  return !!(extendedEmoji.hasOwnProperty(code) || emojiHash.hasOwnProperty(code));
 }
 
 function imageFor(code) {
+  code = code.toLowerCase();
   var url = urlFor(code);
   if (url) {
     return ['img', { href: url, title: ':' + code + ':', 'class': 'emoji', alt: code }];
@@ -145,7 +148,7 @@ Object.keys(translations).forEach(function (t) {
 });
 
 function escapeRegExp(s) {
-  return s.replace(/[-/\\^$*+?.()|[\]{}]/g, '\\$&');
+  return s.replace(/[-/\\^$*+?.()|[\]{}]/gi, '\\$&');
 }
 
 var translationColonRegexp = new RegExp(Object.keys(translationsWithColon).map(function (t) {
diff --git a/spec/components/pretty_text_spec.rb b/spec/components/pretty_text_spec.rb
index c6543aaf4bc..7dda67ae999 100644
--- a/spec/components/pretty_text_spec.rb
+++ b/spec/components/pretty_text_spec.rb
@@ -299,7 +299,6 @@ describe PrettyText do
     end
   end
 
-
   it 'can escape *' do
     expect(PrettyText.cook("***a***a")).to match_html("<p><strong><em>a</em></strong>a</p>")
     expect(PrettyText.cook("***\\****a")).to match_html("<p><strong><em>*</em></strong>a</p>")