diff --git a/css/options.css b/css/options.css
index bbf3f42..9fa666f 100644
--- a/css/options.css
+++ b/css/options.css
@@ -12,6 +12,10 @@ select {
   margin-bottom: 10px;
 }
 
+textarea {
+  margin-bottom: 10px;
+}
+
 pre {
   left: -10px;
   top: 10px;
diff --git a/js/background.js b/js/background.js
index 6192283..3f76fac 100644
--- a/js/background.js
+++ b/js/background.js
@@ -77,7 +77,8 @@
     theme: 'sunburst',
     font: 'Inconsolata',
     fontSize: 'medium',
-    lineNumbers: true
+    lineNumbers: true,
+    extBlacklist: ''
   };
 
   const OPTIONS = Object.keys(OPTIONS_DEFAULTS);
@@ -121,6 +122,17 @@
     return filename.split('.').pop();
   }
 
+  function isExtensionBlacklisted(extension) {
+    var blacklist = localStorage.getItem('extBlacklist').split(/[\s,]+/);
+    var index, length = blacklist.length;
+    for (index = 0; index < length; index++) {
+      if (blacklist[index].toLowerCase() === extension) {
+        return true;
+      }
+    }
+    return false;
+  }
+
   function getFragmentFromUrl(url) {
     var fragment = /#ft=(\w+)/.exec(url);
     return fragment && fragment[1];
@@ -130,6 +142,9 @@
     if (BROWSER_CONTENT.indexOf(contentType) != -1) {
       return null;
     }
+    if (isExtensionBlacklisted(extension)) {
+      return null;
+    }
     return !!LANG_EXT_MAP[fragment] ?  fragment : EXT_LANG_MAP[contentType] ||
                                                   EXT_LANG_MAP[extension]   ||
                                                   EXT_LANG_MAP[filename];
diff --git a/js/options.js b/js/options.js
index d5272ec..060afbd 100644
--- a/js/options.js
+++ b/js/options.js
@@ -43,6 +43,12 @@
         codeEl.innerHTML = codeEl.textContent;
         hljs.highlightBlock(codeEl);
       }
+    },
+    extBlacklist: {
+      selector: '#ext-blacklist',
+      value: 'value',
+      decode: id,
+      render: function(value) {}
     }
   };
 
diff --git a/options.html b/options.html
index d1b00fc..f70c78b 100644
--- a/options.html
+++ b/options.html
@@ -91,6 +91,8 @@ <h3>Select your font size</h3>
         <option value="x-large">x-large</option>
         <option value="xx-large">xx-large</option>
       </select>
+      <h3>Blacklist Extensions</h3>
+      <textarea id="ext-blacklist"></textarea>
       <h3>Line numbers:<input id="line-numbers" type="checkbox"></h3>
       <pre id="code" class="go">
 package main