diff --git a/lib/Minify.php b/lib/Minify.php
index 9c56bff..e5f1a5c 100644
--- a/lib/Minify.php
+++ b/lib/Minify.php
@@ -93,10 +93,10 @@ class Minify {
      * 'contentTypeCharset' : appended to the Content-Type header sent. Set to a falsey
      * value to remove. (default 'UTF-8')  
      * 
-     * 'setExpires' : set this to a timestamp to have Minify send an HTTP Expires
-     * header instead of checking for conditional GET (default null). 
-     * E.g. ($_SERVER['REQUEST_TIME'] + 86400 * 365) for 1yr 
-     * Note this has nothing to do with server-side caching.
+     * 'maxAge' : set this to the number of seconds the client should use its cache
+     * before revalidating with the server. This sets Cache-Control: max-age and the
+     * Expires header. Unlike the old 'setExpires' setting, this setting will NOT
+     * prevent conditional GETs. Note this has nothing to do with server-side caching.
      * 
      * 'debug' : set to true to minify all sources with the 'Lines' controller, which
      * eases the debugging of combined files. This also prevents 304 responses.
@@ -148,6 +148,7 @@ class Minify {
         $options = $controller->analyzeSources($options);
         self::$_options = $controller->mixInDefaultOptions($options);
         
+        // check request validity
         if (! $controller->sources) {
             // invalid request!
             if (! self::$_options['quiet']) {
@@ -169,44 +170,36 @@ class Minify {
         
         if (self::$_options['debug']) {
             self::_setupDebug($controller->sources);
-            self::$_options['setExpires'] = time();
+            self::$_options['maxAge'] = 0;
         }
-
-        if (null === self::$_options['setExpires']) {
-            // conditional GET
-            require_once 'HTTP/ConditionalGet.php';
-            $cg = new HTTP_ConditionalGet(array(
-                'lastModifiedTime' => self::$_options['lastModifiedTime']
-                ,'isPublic' => self::$_options['isPublic']
-            ));
-            if ($cg->cacheIsValid) {
-                // client's cache is valid
-                if (! self::$_options['quiet']) {
-                    $cg->sendHeaders();
-                    return;
-                } else {
-                    return array(
-                        'success' => true
-                        ,'statusCode' => 304 
-                        ,'content' => ''
-                        ,'headers' => array()
-                    );    
-                }
+        
+        // check client cache
+        require_once 'HTTP/ConditionalGet.php';
+        $cgOptions = array(
+        	'lastModifiedTime' => self::$_options['lastModifiedTime']
+            ,'isPublic' => self::$_options['isPublic']
+        );
+        if (null !== self::$_options['maxAge']) {
+            $cgOptions['maxAge'] = self::$_options['maxAge'];
+        }
+        $cg = new HTTP_ConditionalGet($cgOptions);
+        if ($cg->cacheIsValid) {
+            // client's cache is valid
+            if (! self::$_options['quiet']) {
+                $cg->sendHeaders();
+                return;
             } else {
-                // client will need output
-                $headers = $cg->getHeaders();
-                unset($cg);
+                return array(
+                    'success' => true
+                    ,'statusCode' => 304 
+                    ,'content' => ''
+                    ,'headers' => $cg->getHeaders()
+                );
             }
         } else {
-            // don't need conditional GET
-            $privacy = self::$_options['isPublic']
-                ? 'public'
-                : 'private';
-            $headers = array(
-                'Cache-Control' => $privacy . ', max-age=' 
-                    . (self::$_options['setExpires'] - $_SERVER['REQUEST_TIME'])
-                ,'Expires' => gmdate('D, d M Y H:i:s \G\M\T', self::$_options['setExpires'])
-            );
+            // client will need output
+            $headers = $cg->getHeaders();
+            unset($cg);
         }
         
         // determine encoding
@@ -226,6 +219,7 @@ class Minify {
             self::$_options['encodeMethod'] = ''; // identity (no encoding)
         }
         
+        // check server cache
         if (null !== self::$_cache) {
             // using cache
             // the goal is to use only the cache methods to sniff the length and 
diff --git a/lib/Minify/Controller/Base.php b/lib/Minify/Controller/Base.php
index 7a54435..5f3390b 100644
--- a/lib/Minify/Controller/Base.php
+++ b/lib/Minify/Controller/Base.php
@@ -45,7 +45,7 @@ abstract class Minify_Controller_Base {
             ,'encodeLevel' => 9
             ,'minifierOptions' => array() // no minifier options
             ,'contentTypeCharset' => 'UTF-8'
-            ,'setExpires' => null // use conditional GET
+            ,'maxAge' => null // no Expires/max-age
             ,'quiet' => false // serve() will send headers and output
             ,'debug' => false
             
diff --git a/web/test/test_Minify.php b/web/test/test_Minify.php
index fe8e004..6c5a12e 100644
--- a/web/test/test_Minify.php
+++ b/web/test/test_Minify.php
@@ -23,7 +23,12 @@ function test_Minify()
     	'success' => true
         ,'statusCode' => 304    
         ,'content' => '',
-        'headers' => array()
+        'headers' => array(
+        	'Last-Modified' => gmdate('D, d M Y H:i:s \G\M\T', $lastModified),
+            'ETag' => "\"{$lastModified}pub\"",	
+        	'Cache-Control' => 'max-age=0, public, must-revalidate',
+        	'_responseCode' => 'HTTP/1.0 304 Not Modified',
+        )
     );
     $output = Minify::serve('Files', array(
         'files' => $thisDir . '/_test_files/css/styles.css' // controller casts to array
@@ -43,20 +48,24 @@ function test_Minify()
         //! class_exists('Cache_Lite_File', false)
         ! class_exists('HTTP_Encoder', false)
         && ! class_exists('Minify_CSS', false)
-        ,'Encoder.php, CSS.php not loaded'
+        && ! class_exists('Minify_Cache', false)
+        ,'Encoder.php, CSS.php, Cache.php not loaded'
     );
     
     // Test minifying JS and serving with Expires header
     
     $content = preg_replace('/\\r\\n?/', "\n", file_get_contents($minifyTestPath . '/minified.js'));
+    $lastModified = filemtime($minifyTestPath . '/minified.js');
     $expected = array(
     	'success' => true
         ,'statusCode' => 200
         // Minify_Javascript always converts to \n line endings
         ,'content' => $content
         ,'headers' => array (
-            'Cache-Control' => 'public, max-age=86400',
-            'Expires' => gmdate('D, d M Y H:i:s \G\M\T', $tomorrow),
+        	'Expires' => gmdate('D, d M Y H:i:s \G\M\T', $tomorrow),
+        	'Last-Modified' => gmdate('D, d M Y H:i:s \G\M\T', $lastModified),
+        	'ETag' => "\"{$lastModified}pub\"",	
+        	'Cache-Control' => 'max-age=86400, public, must-revalidate',
             'Content-Length' => strlen($content),
             'Content-Type' => 'application/x-javascript; charset=UTF-8',
         )
@@ -67,7 +76,7 @@ function test_Minify()
             ,$minifyTestPath . '/QueryString.js'
         )
         ,'quiet' => true
-        ,'setExpires' => $tomorrow
+        ,'maxAge' => 86400
         ,'encodeOutput' => false
     ));
     $passed = assertTrue($expected === $output, 'Minify : JS and Expires');