diff --git a/lib/ace/mode/ruby_highlight_rules.js b/lib/ace/mode/ruby_highlight_rules.js
index cc2464ef..0d0cabac 100644
--- a/lib/ace/mode/ruby_highlight_rules.js
+++ b/lib/ace/mode/ruby_highlight_rules.js
@@ -125,13 +125,13 @@ var RubyHighlightRules = function() {
                 regex : "[A-Z](?:[a-zA-Z_]|\d)+"
 	        }, {
                 token : "string", // symbol
-                regex : "[:](?:[a-zA-Z]|\d)+"
-	        }, {
+                regex : "[:](?:[A-Za-z_]|[@$](?=[a-zA-Z0-9_]))[a-zA-Z0-9_]*[!=?]?"
+	       }, {
 	            token : "constant.numeric", // hex
-	            regex : "0[xX][0-9a-fA-F]+\\b"
+	            regex : "0[xX][0-9a-fA-F](?:[0-9a-fA-F]|_(?=[0-9a-fA-F]))*\\b"
 	        }, {
 	            token : "constant.numeric", // float
-	            regex : "[+-]?\\d+(?:(?:\\.\\d*)?(?:[eE][+-]?\\d+)?)?\\b"
+	            regex : "[+-]?\\d(?:\\d|_(?=\\d))*(?:(?:\\.\\d(?:\\d|_(?=\\d))*)?(?:[eE][+-]?\\d+)?)?\\b"
 	        }, {
 	            token : "constant.language.boolean",
 	            regex : "(?:true|false)\\b"
diff --git a/lib/ace/mode/ruby_tokenizer_test.js b/lib/ace/mode/ruby_tokenizer_test.js
new file mode 100644
index 00000000..f8dd7eb8
--- /dev/null
+++ b/lib/ace/mode/ruby_tokenizer_test.js
@@ -0,0 +1,107 @@
+/* ***** BEGIN LICENSE BLOCK *****
+ * Version: MPL 1.1/GPL 2.0/LGPL 2.1
+ *
+ * The contents of this file are subject to the Mozilla Public License Version
+ * 1.1 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ * http://www.mozilla.org/MPL/
+ *
+ * Software distributed under the License is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
+ * for the specific language governing rights and limitations under the
+ * License.
+ *
+ * The Original Code is Ajax.org Code Editor (ACE).
+ *
+ * The Initial Developer of the Original Code is
+ * Ajax.org B.V.
+ * Portions created by the Initial Developer are Copyright (C) 2010
+ * the Initial Developer. All Rights Reserved.
+ *
+ * Contributor(s):
+ *      Fabian Jakobs <fabian AT ajax DOT org>
+ *      Trent Ogren <me AT trentogren DOT com>
+ *
+ * Alternatively, the contents of this file may be used under the terms of
+ * either the GNU General Public License Version 2 or later (the "GPL"), or
+ * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
+ * in which case the provisions of the GPL or the LGPL are applicable instead
+ * of those above. If you wish to allow use of your version of this file only
+ * under the terms of either the GPL or the LGPL, and not to allow others to
+ * use your version of this file under the terms of the MPL, indicate your
+ * decision by deleting the provisions above and replace them with the notice
+ * and other provisions required by the GPL or the LGPL. If you do not delete
+ * the provisions above, a recipient may use your version of this file under
+ * the terms of any one of the MPL, the GPL or the LGPL.
+ *
+ * ***** END LICENSE BLOCK ***** */
+
+if (typeof process !== "undefined") {
+    require("../../../support/paths");
+}
+
+define(function(require, exports, module) {
+
+var RubyMode = require("ace/mode/ruby").Mode;
+var assert = require("ace/test/assertions");
+
+module.exports = {
+    setUp : function() {
+        console.log("setUp", this);
+        this.tokenizer = new RubyMode().getTokenizer();
+    },
+
+    "test: symbol tokenizer" : function() {
+        // https://gist.github.com/1072693
+        assertValidTokens(this.tokenizer, "string",
+          [":@thing", ":$thing", ":_thing", ":thing", ":Thing", ":thing1", ":thing_a",
+              ":THING", ":thing!", ":thing=", ":thing?", ":t?"]);
+        assertInvalidTokens(this.tokenizer, "string",
+          [":", ":@", ":$", ":1", ":1thing", ":th?ing", ":thi=ng", ":1thing",
+            ":th!ing", ":thing#"]);
+    },
+
+    "test: hex tokenizer" : function() {
+        assertValidTokens(this.tokenizer, "constant.numeric",
+            ["0x9a", "0XA1", "0x9_a"]);
+        assertInvalidTokens(this.tokenizer, "constant.numeric",
+            ["0x", "0x_9a", "0x9a_"]);
+    },
+
+    "test: float tokenizer" : function() {
+        assertValidTokens(this.tokenizer, "constant.numeric",
+            ["1", "+1", "-1", "12_345", "0.000_1"]);
+        assertInvalidTokens(this.tokenizer, "constant.numeric",
+            ["_", "_1", "1_", "1_.0", "0._1"]);
+    }
+};
+
+function assertValidTokens(tokenizer, tokenType, validTokens) {
+    for (var i = 0, length = validTokens.length; i < length; i++) {
+        var validToken = validTokens[i],
+            tokens = tokenizer.getLineTokens(validToken, "start").tokens;
+        console.log("validToken", validToken);
+        console.log("tokens", tokens);
+        assert.equal(tokens[0].value, validToken,
+          '"' + validToken + '" should be one token');
+        assert.equal(tokens[0].type, tokenType,
+          '"' + validToken + '" should be a "' + tokenType + '" token');
+    }
+}
+
+function assertInvalidTokens(tokenizer, tokenType, invalidTokens) {
+    for (var i = 0, length = invalidTokens.length; i < length; i++) {
+        var invalidToken = invalidTokens[i],
+            tokens = tokenizer.getLineTokens(invalidToken, "start").tokens;
+        console.log("invalidToken", invalidToken);
+        console.log("tokens", tokens);
+        assert.ok(tokens[0].type !== tokenType || tokens[0].value !== invalidToken,
+          '"' + invalidToken + '" is not a valid "' + tokenType + '"');
+    }
+}
+
+});
+
+if (typeof module !== "undefined" && module === require.main) {
+    require("asyncjs").test.testcase(module.exports).exec()
+}
diff --git a/lib/ace/test/all_browser.js b/lib/ace/test/all_browser.js
index 97a28a16..9c7c0d79 100644
--- a/lib/ace/test/all_browser.js
+++ b/lib/ace/test/all_browser.js
@@ -28,6 +28,7 @@ var tests = [
      require("ace/mode/html_tokenizer_test"),
      require("ace/mode/javascript_test"),
      require("ace/mode/javascript_tokenizer_test"),
+     require("ace/mode/ruby_tokenizer_test"),
      require("ace/mode/text_test"),
      require("ace/mode/xml_test"),
      require("ace/mode/xml_tokenizer_test")