diff --git a/CHANGELOG.md b/CHANGELOG.md
index c7dd144..e7a6f4d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,7 +3,9 @@
 
 - Added footnotes support.
 - Added definitions lists support.
-- Exposed `./common/utils` to simplify custom renderer write.
+- Added `fence_custom` renderer extension to easy override
+  named fenced blocks (useful for diagrams and so on).
+- Exposed `./common/utils` to simplify custom renderers.
 
 
 1.4.1 / 2014-11-13
diff --git a/lib/renderer.js b/lib/renderer.js
index 1da33eb..2a92f2a 100644
--- a/lib/renderer.js
+++ b/lib/renderer.js
@@ -55,16 +55,29 @@ rules.code = function (tokens, idx /*, options, env */) {
 };
 
 
-rules.fence = function (tokens, idx, options /*, env */) {
+rules.fence = function (tokens, idx, options, env, self) {
   var token = tokens[idx];
   var langClass = '';
   var langPrefix = options.langPrefix;
-  var params, langName = '';
+  var langName = '', fenceName;
   var highlighted;
 
   if (token.params) {
-    params = token.params.split(/ +/g);
-    langName = escapeHtml(replaceEntities(unescapeMd(params[0])));
+
+    //
+    // ```foo bar
+    //
+    // Try custom renderer "foo" first. That will simplify overwrite
+    // for diagrams, latex, and any other fenced block with custom look
+    //
+
+    fenceName = token.params.split(/\s+/g)[0];
+
+    if (self.rules.fence_custom.hasOwnProperty(fenceName)) {
+      return self.rules.fence_custom[fenceName](tokens, idx, options, env, self);
+    }
+
+    langName = escapeHtml(replaceEntities(unescapeMd(fenceName)));
     langClass = ' class="' + langPrefix + langName + '"';
   }
 
@@ -80,6 +93,7 @@ rules.fence = function (tokens, idx, options /*, env */) {
         + '</code></pre>' + getBreak(tokens, idx);
 };
 
+rules.fence_custom = {};
 
 rules.heading_open = function (tokens, idx /*, options, env */) {
   return '<h' + tokens[idx].hLevel + '>';
@@ -310,6 +324,8 @@ rules.dd_close = function() {
 function Renderer() {
   // Clone rules object to allow local modifications
   this.rules = assign({}, rules);
+  // exported helper, for custom rules only
+  this.getBreak = getBreak;
 }
 
 
@@ -318,7 +334,7 @@ Renderer.prototype.renderInline = function (tokens, options, env) {
       _rules = this.rules;
 
   for (var i = 0, len = tokens.length; i < len; i++) {
-    result += _rules[tokens[i].type](tokens, i, options, env);
+    result += _rules[tokens[i].type](tokens, i, options, env, this);
   }
 
   return result;
@@ -334,7 +350,7 @@ Renderer.prototype.render = function (tokens, options, env) {
     if (tokens[i].type === 'inline') {
       result += this.renderInline(tokens[i].children, options, env);
     } else {
-      result += _rules[tokens[i].type](tokens, i, options, env);
+      result += _rules[tokens[i].type](tokens, i, options, env, this);
     }
   }
 
diff --git a/test/misc.js b/test/misc.js
index e8f380c..c2f9d3d 100644
--- a/test/misc.js
+++ b/test/misc.js
@@ -4,6 +4,7 @@
 
 var assert     = require('assert');
 var Remarkable = require('../');
+var utils      = require('../').utils;
 
 
 describe('Utils', function () {
@@ -181,3 +182,23 @@ describe('Links validation', function () {
   });
 
 });
+
+
+describe('Custom fences', function () {
+
+  it('should render differently overriden rule', function () {
+    var md = new Remarkable();
+
+    md.renderer.rules.fence_custom.foo = function (tokens, idx, options, env, self) {
+      return '<div class="foo">' +
+             utils.escapeHtml(tokens[idx].content) +
+             '</div>' + self.getBreak(tokens, idx);
+    };
+
+    var text = '```foo bar\n' +
+               '123&45\n' +
+               '```';
+    assert.strictEqual(md.render(text), '<div class="foo">123&amp;45\n</div>\n');
+  });
+
+});