diff --git a/docs/core/variables.md b/docs/core/variables.md
index c2b99ba..cf2ea0e 100644
--- a/docs/core/variables.md
+++ b/docs/core/variables.md
@@ -42,6 +42,7 @@ Sections of CSS can be included and excluded on the basis of variable existence
 
 ```crush
 @set foo #f00;
+@set bar true;
 
 @ifset foo {
   p {
@@ -54,5 +55,8 @@ p {
   @ifset not foo {
     line-height: 1.5;
   }
+  @ifset bar(true) {
+    margin-bottom: 5px;
+  }
 }
-```
+```
\ No newline at end of file
diff --git a/lib/CssCrush/Process.php b/lib/CssCrush/Process.php
index b3c1607..c15c7ee 100644
--- a/lib/CssCrush/Process.php
+++ b/lib/CssCrush/Process.php
@@ -457,7 +457,7 @@ protected function resolveSettings()
 
     protected function resolveIfDefines()
     {
-        $ifdefinePatt = Regex::make('~@if(?:set|define) \s+ (?<negate>not \s+)? (?<name>{{ ident }}) \s* \{~ixS');
+        $ifdefinePatt = Regex::make('~@if(?:set|define) \s+ (?<negate>not \s+)? (?<name>{{ ident }}) \s* {{ parens }}? \s* \{~ixS');
 
         $matches = $this->string->matchAll($ifdefinePatt);
 
@@ -472,7 +472,20 @@ protected function resolveIfDefines()
             $negate = $match['negate'][1] != -1;
             $nameDefined = isset($this->vars[$match['name'][0]]);
 
-            if (! $negate && $nameDefined || $negate && ! $nameDefined) {
+            $valueDefined = isset($match['parens_content'][0]);
+            $valueMatch = false;
+            if ($nameDefined && $valueDefined) {
+                $testValue = Util::rawValue(trim($match['parens_content'][0]));
+                $varValue = Util::rawValue($this->vars[$match['name'][0]]);
+                $valueMatch = $varValue == $testValue;
+            }
+
+            if (
+                ( $valueDefined && !$negate && $valueMatch )
+                || ( $valueDefined && $negate && !$valueMatch )
+                || ( !$valueDefined && !$negate && $nameDefined )
+                || ( !$valueDefined && $negate && !$nameDefined )
+            ) {
                 $curlyMatch->unWrap();
             }
             else {
diff --git a/lib/CssCrush/Regex.php b/lib/CssCrush/Regex.php
index eaa0218..1928eb5 100644
--- a/lib/CssCrush/Regex.php
+++ b/lib/CssCrush/Regex.php
@@ -85,6 +85,7 @@ public static function init()
         $patt->ruleDirective = '~^(?:(@include)|(@extends?)|(@name))[\s]+~iS';
         $patt->argListSplit = '~\s*[,\s]\s*~S';
         $patt->cruftyHex = Regex::make('~\#({{hex}})\1({{hex}})\2({{hex}})\3~S');
+        $patt->token = Regex::make('~^ \? (?<type>[a-zA-Z]) {{token_id}} \? $~xS');
     }
 
     public static function make($pattern)
diff --git a/lib/CssCrush/Tokens.php b/lib/CssCrush/Tokens.php
index cd794ff..43a1475 100644
--- a/lib/CssCrush/Tokens.php
+++ b/lib/CssCrush/Tokens.php
@@ -146,11 +146,16 @@ public static function pad($label, $replaced_text)
 
     public static function is($label, $of_type)
     {
-        if (preg_match(Regex::make('~^ \? (?<type>[a-zA-Z]) {{token_id}} \? $~xS'), $label, $m)) {
+        if (preg_match(Regex::$patt->token, $label, $m)) {
 
             return $of_type ? ($of_type === $m['type']) : true;
         }
 
         return false;
     }
+
+    public static function test($value)
+    {
+        return preg_match(Regex::$patt->token, $value, $m) ? $m['type'] : false;
+    }
 }
diff --git a/lib/CssCrush/Util.php b/lib/CssCrush/Util.php
index f3a5d00..4f02c32 100644
--- a/lib/CssCrush/Util.php
+++ b/lib/CssCrush/Util.php
@@ -228,6 +228,23 @@ public static function readConfigFile($path)
         return Options::filter(get_defined_vars());
     }
 
+    /*
+     * Get raw value (useful if testing values that may or may not be a token).
+     */
+    public static function rawValue($value)
+    {
+        if ($tokenType = Tokens::test($value)) {
+            if ($tokenType == 'u') {
+                $value = Crush::$process->tokens->get($value)->value;
+            }
+            elseif ($tokenType == 's') {
+                $value = Crush::$process->tokens->get($value);
+            }
+        }
+
+        return $value;
+    }
+
     /*
      * Encode integer to Base64 VLQ.
      */
diff --git a/tests/unit/CssCrush/TokensTest.php b/tests/unit/CssCrush/TokensTest.php
index f544ca0..2c4880a 100644
--- a/tests/unit/CssCrush/TokensTest.php
+++ b/tests/unit/CssCrush/TokensTest.php
@@ -111,4 +111,11 @@ public function testIs()
     {
         $this->assertTrue(Tokens::is($this->tokens->createLabel('s'), 's'));
     }
+
+    public function testTest()
+    {
+        $this->assertFalse(Tokens::test('foobar'));
+        $this->assertEquals(Tokens::test($this->tokens->createLabel('u')), 'u');
+        $this->assertEquals(Tokens::test($this->tokens->createLabel('s')), 's');
+    }
 }
diff --git a/tests/unit/CssCrush/UtilTest.php b/tests/unit/CssCrush/UtilTest.php
index c50aefe..04536cd 100644
--- a/tests/unit/CssCrush/UtilTest.php
+++ b/tests/unit/CssCrush/UtilTest.php
@@ -3,9 +3,17 @@
 namespace CssCrush\UnitTest;
 
 use CssCrush\Util;
+use CssCrush\Tokens;
+use CssCrush\Url;
 
 class UtilTest extends \PHPUnit_Framework_TestCase
 {
+    public function setUp()
+    {
+        $this->process = bootstrap_process(array('minify' => false));
+        $this->tokens = $this->process->tokens;
+    }
+
     public function testNormalizePath()
     {
         $this->assertEquals('/Some/crazy/Path', Util::normalizePath('C:\\Some\crazy/Path\\', true));
@@ -90,6 +98,24 @@ public function testFilePutContents()
         $this->assertTrue(Util::filePutContents($test_file, 'Hello Mum'));
     }
 
+    public function testRawValue()
+    {
+        $url1 = $this->tokens->add(new Url('foo.jpg'));
+        $url2 = $this->tokens->add(new Url('foo.jpg'));
+        $this->assertNotEquals($url1, $url2);
+        $this->assertEquals(Util::rawValue($url1), Util::rawValue($url2));
+        $this->assertEquals(Util::rawValue($url1), 'foo.jpg');
+
+        $string1 = $this->tokens->add('"bar"', 's');
+        $string2 = $this->tokens->add('"bar"', 's');
+        $this->assertNotEquals($string1, $string2);
+        $this->assertEquals(Util::rawValue($string1), Util::rawValue($string2));
+        $this->assertEquals(Util::rawValue($string1), '"bar"');
+
+        $this->assertEquals(Util::rawValue('foobar'), 'foobar');
+        $this->assertNotEquals(Util::rawValue('foobar'), 'notFoobar');
+    }
+
     public function testReadConfigFile()
     {
         $contents = <<<'NOW_DOC'