diff --git a/lib/Twig/Extension/Core.php b/lib/Twig/Extension/Core.php
index b7d2dfc2c..de55b3871 100644
--- a/lib/Twig/Extension/Core.php
+++ b/lib/Twig/Extension/Core.php
@@ -386,7 +386,7 @@ function twig_random(Twig_Environment $env, $values = null)
             return '';
         }
         if (null !== $charset = $env->getCharset()) {
-            if ('UTF-8' != $charset) {
+            if ('UTF-8' !== $charset) {
                 $values = twig_convert_encoding($values, 'UTF-8', $charset);
             }
 
@@ -394,7 +394,7 @@ function twig_random(Twig_Environment $env, $values = null)
             // split at all positions, but not after the start and not before the end
             $values = preg_split('/(?<!^)(?!$)/u', $values);
 
-            if ('UTF-8' != $charset) {
+            if ('UTF-8' !== $charset) {
                 foreach ($values as $i => $value) {
                     $values[$i] = twig_convert_encoding($value, $charset, 'UTF-8');
                 }
@@ -919,7 +919,7 @@ function twig_reverse_filter(Twig_Environment $env, $item, $preserveKeys = false
     if (null !== $charset = $env->getCharset()) {
         $string = (string) $item;
 
-        if ('UTF-8' != $charset) {
+        if ('UTF-8' !== $charset) {
             $item = twig_convert_encoding($string, 'UTF-8', $charset);
         }
 
@@ -927,7 +927,7 @@ function twig_reverse_filter(Twig_Environment $env, $item, $preserveKeys = false
 
         $string = implode('', array_reverse($matches[0]));
 
-        if ('UTF-8' != $charset) {
+        if ('UTF-8' !== $charset) {
             $string = twig_convert_encoding($string, $charset, 'UTF-8');
         }
 
@@ -1053,7 +1053,7 @@ function twig_escape_filter(Twig_Environment $env, $string, $strategy = 'html',
         case 'js':
             // escape all non-alphanumeric characters
             // into their \xHH or \uHHHH representations
-            if ('UTF-8' != $charset) {
+            if ('UTF-8' !== $charset) {
                 $string = twig_convert_encoding($string, 'UTF-8', $charset);
             }
 
@@ -1063,14 +1063,14 @@ function twig_escape_filter(Twig_Environment $env, $string, $strategy = 'html',
 
             $string = preg_replace_callback('#[^a-zA-Z0-9,\._]#Su', '_twig_escape_js_callback', $string);
 
-            if ('UTF-8' != $charset) {
+            if ('UTF-8' !== $charset) {
                 $string = twig_convert_encoding($string, $charset, 'UTF-8');
             }
 
             return $string;
 
         case 'css':
-            if ('UTF-8' != $charset) {
+            if ('UTF-8' !== $charset) {
                 $string = twig_convert_encoding($string, 'UTF-8', $charset);
             }
 
@@ -1080,14 +1080,14 @@ function twig_escape_filter(Twig_Environment $env, $string, $strategy = 'html',
 
             $string = preg_replace_callback('#[^a-zA-Z0-9]#Su', '_twig_escape_css_callback', $string);
 
-            if ('UTF-8' != $charset) {
+            if ('UTF-8' !== $charset) {
                 $string = twig_convert_encoding($string, $charset, 'UTF-8');
             }
 
             return $string;
 
         case 'html_attr':
-            if ('UTF-8' != $charset) {
+            if ('UTF-8' !== $charset) {
                 $string = twig_convert_encoding($string, 'UTF-8', $charset);
             }
 
@@ -1097,7 +1097,7 @@ function twig_escape_filter(Twig_Environment $env, $string, $strategy = 'html',
 
             $string = preg_replace_callback('#[^a-zA-Z0-9,\.\-_]#Su', '_twig_escape_html_attr_callback', $string);
 
-            if ('UTF-8' != $charset) {
+            if ('UTF-8' !== $charset) {
                 $string = twig_convert_encoding($string, $charset, 'UTF-8');
             }
 
@@ -1275,7 +1275,7 @@ if (function_exists('mb_get_info')) {
      */
     function twig_upper_filter(Twig_Environment $env, $string)
     {
-        if (null !== ($charset = $env->getCharset())) {
+        if (null !== $charset = $env->getCharset()) {
             return mb_strtoupper($string, $charset);
         }
 
@@ -1292,7 +1292,7 @@ if (function_exists('mb_get_info')) {
      */
     function twig_lower_filter(Twig_Environment $env, $string)
     {
-        if (null !== ($charset = $env->getCharset())) {
+        if (null !== $charset = $env->getCharset()) {
             return mb_strtolower($string, $charset);
         }
 
@@ -1309,7 +1309,7 @@ if (function_exists('mb_get_info')) {
      */
     function twig_title_string_filter(Twig_Environment $env, $string)
     {
-        if (null !== ($charset = $env->getCharset())) {
+        if (null !== $charset = $env->getCharset()) {
             return mb_convert_case($string, MB_CASE_TITLE, $charset);
         }