diff --git a/min/lib/HTTP/ConditionalGet.php b/min/lib/HTTP/ConditionalGet.php
index 93b7e75..41dfd2e 100644
--- a/min/lib/HTTP/ConditionalGet.php
+++ b/min/lib/HTTP/ConditionalGet.php
@@ -355,7 +355,10 @@ class HTTP_ConditionalGet {
         }
         // strip off IE's extra data (semicolon)
         list($ifModifiedSince) = explode(';', $_SERVER['HTTP_IF_MODIFIED_SINCE'], 2);
-        if (strtotime($ifModifiedSince) >= $this->_lmTime) {
+
+        $date = new DateTime($ifModifiedSince, new DateTimeZone('UTC'));
+
+        if ($date->getTimestamp() >= $this->_lmTime) {
             // Apache 2.2's behavior. If there was no ETag match, send the 
             // non-encoded version of the ETag value.
             $this->_headers['ETag'] = $this->normalizeEtag($this->_etag);