diff --git a/lib/Minify/HTML.php b/lib/Minify/HTML.php
index 0eb9565..c3453f5 100644
--- a/lib/Minify/HTML.php
+++ b/lib/Minify/HTML.php
@@ -99,36 +99,36 @@ class Minify_HTML
 
         // replace SCRIPTs (and minify) with placeholders
         $this->_html = preg_replace_callback(
-            '/(\\s*)<script(\\b[^>]*?>)([\\s\\S]*?)<\\/script>(\\s*)/i'
+            '/(\\s*)<script(\\b[^>]*?>)([\\s\\S]*?)<\\/script>(\\s*)/iu'
             ,array($this, '_removeScriptCB')
             ,$this->_html);
 
         // replace STYLEs (and minify) with placeholders
         $this->_html = preg_replace_callback(
-            '/\\s*<style(\\b[^>]*>)([\\s\\S]*?)<\\/style>\\s*/i'
+            '/\\s*<style(\\b[^>]*>)([\\s\\S]*?)<\\/style>\\s*/iu'
             ,array($this, '_removeStyleCB')
             ,$this->_html);
 
         // remove HTML comments (not containing IE conditional comments).
         $this->_html = preg_replace_callback(
-            '/<!--([\\s\\S]*?)-->/'
+            '/<!--([\\s\\S]*?)-->/u'
             ,array($this, '_commentCB')
             ,$this->_html);
 
         // replace PREs with placeholders
-        $this->_html = preg_replace_callback('/\\s*<pre(\\b[^>]*?>[\\s\\S]*?<\\/pre>)\\s*/i'
+        $this->_html = preg_replace_callback('/\\s*<pre(\\b[^>]*?>[\\s\\S]*?<\\/pre>)\\s*/iu'
             ,array($this, '_removePreCB')
             ,$this->_html);
 
         // replace TEXTAREAs with placeholders
         $this->_html = preg_replace_callback(
-            '/\\s*<textarea(\\b[^>]*?>[\\s\\S]*?<\\/textarea>)\\s*/i'
+            '/\\s*<textarea(\\b[^>]*?>[\\s\\S]*?<\\/textarea>)\\s*/iu'
             ,array($this, '_removeTextareaCB')
             ,$this->_html);
 
         // trim each line.
         // @todo take into account attribute values that span multiple lines.
-        $this->_html = preg_replace('/^\\s+|\\s+$/m', '', $this->_html);
+        $this->_html = preg_replace('/^\\s+|\\s+$/mu', '', $this->_html);
 
         // remove ws around block/undisplayed elements
         $this->_html = preg_replace('/\\s+(<\\/?(?:area|article|aside|base(?:font)?|blockquote|body'
@@ -139,12 +139,12 @@ class Minify_HTML
 
         // remove ws outside of all elements
         $this->_html = preg_replace(
-            '/>(\\s(?:\\s*))?([^<]+)(\\s(?:\s*))?</'
+            '/>(\\s(?:\\s*))?([^<]+)(\\s(?:\s*))?</u'
             ,'>$1$2$3<'
             ,$this->_html);
 
         // use newlines before 1st attribute in open tags (to limit line lengths)
-        $this->_html = preg_replace('/(<[a-z\\-]+)\\s+([^>]+>)/i', "$1\n$2", $this->_html);
+        $this->_html = preg_replace('/(<[a-z\\-]+)\\s+([^>]+>)/iu', "$1\n$2", $this->_html);
 
         // fill placeholders
         $this->_html = str_replace(
@@ -198,7 +198,7 @@ class Minify_HTML
         $openStyle = "<style{$m[1]}";
         $css = $m[2];
         // remove HTML comments
-        $css = preg_replace('/(?:^\\s*<!--|-->\\s*$)/', '', $css);
+        $css = preg_replace('/(?:^\\s*<!--|-->\\s*$)/u', '', $css);
 
         // remove CDATA section markers
         $css = $this->_removeCdata($css);
@@ -226,7 +226,7 @@ class Minify_HTML
 
         // remove HTML comments (and ending "//" if present)
         if ($this->_jsCleanComments) {
-            $js = preg_replace('/(?:^\\s*<!--\\s*|\\s*(?:\\/\\/)?\\s*-->\\s*$)/', '', $js);
+            $js = preg_replace('/(?:^\\s*<!--\\s*|\\s*(?:\\/\\/)?\\s*-->\\s*$)/u', '', $js);
         }
 
         // remove CDATA section markers
@@ -253,6 +253,6 @@ class Minify_HTML
 
     protected function _needsCdata($str)
     {
-        return ($this->_isXhtml && preg_match('/(?:[<&]|\\-\\-|\\]\\]>)/', $str));
+        return ($this->_isXhtml && preg_match('/(?:[<&]|\\-\\-|\\]\\]>)/u', $str));
     }
 }