diff --git a/NEW_FEATURES.txt b/NEW_FEATURES.txt
index 43b7ee85..83945638 100644
--- a/NEW_FEATURES.txt
+++ b/NEW_FEATURES.txt
@@ -4,6 +4,12 @@ This file contains a brief description of new features which have been added to
 
 Smarty 3.1.32
 
+    Deprecate functions Smarty::muteExpectedErrors() and Smarty::unmuteExpectedErrors()
+    ===================================================================================
+    These functions to start a special error handler are no longer needed as Smarty does
+    no longer use error suppression like @filemtime().
+    For backward compatibility the functions still can be called.
+
     Using literals containing Smarty's left and right delimiter
     ===========================================================
     New Methods
diff --git a/change_log.txt b/change_log.txt
index ca71190f..812953e8 100644
--- a/change_log.txt
+++ b/change_log.txt
@@ -2,6 +2,10 @@
 26.10.2017  3.1.32-dev-28
   - bugfix Smarty version was  not filled in header comment of compiled and cached  files
   - optimization replace internal Smarty::$ds property by DIRECTORY_SEPARATOR
+  - deprecate functions Smarty::muteExpectedErrors() and Smarty::unmuteExpectedErrors()
+    as Smarty does no longer use error suppression like @filemtime().
+    for backward compatibility code is moved from Smarty class to an external class and still can be
+    called.
 
 21.10.2017
   - bugfix custom delimiters could fail since modification of  version 3.1.32-dev-23
diff --git a/libs/Smarty.class.php b/libs/Smarty.class.php
index 1f6585b9..9a01e160 100644
--- a/libs/Smarty.class.php
+++ b/libs/Smarty.class.php
@@ -100,7 +100,7 @@ class Smarty extends Smarty_Internal_TemplateBase
     /**
      * smarty version
      */
-    const SMARTY_VERSION = '3.1.32-dev-28';
+    const SMARTY_VERSION = '3.1.32-dev-29';
     /**
      * define variable scopes
      */
@@ -166,14 +166,6 @@ class Smarty extends Smarty_Internal_TemplateBase
      * assigned global tpl vars
      */
     public static $global_tpl_vars = array();
-    /**
-     * error handler returned by set_error_handler() in Smarty::muteExpectedErrors()
-     */
-    public static $_previous_error_handler = null;
-    /**
-     * contains directories outside of SMARTY_DIR that are to be muted by muteExpectedErrors()
-     */
-    public static $_muted_directories = array();
     /**
      * Flag denoting if Multibyte String functions are available
      */
@@ -625,99 +617,21 @@ class Smarty extends Smarty_Internal_TemplateBase
         }
     }
 
-    /**
-     * Error Handler to mute expected messages
-     *
-     * @link http://php.net/set_error_handler
-     *
-     * @param  integer $errno Error level
-     * @param          $errstr
-     * @param          $errfile
-     * @param          $errline
-     * @param          $errcontext
-     *
-     * @return bool|void
-     */
-    public static function mutingErrorHandler($errno, $errstr, $errfile, $errline, $errcontext)
-    {
-        $_is_muted_directory = false;
-        // add the SMARTY_DIR to the list of muted directories
-        if (!isset(Smarty::$_muted_directories[ SMARTY_DIR ])) {
-            $smarty_dir = realpath(SMARTY_DIR);
-            if ($smarty_dir !== false) {
-                Smarty::$_muted_directories[ SMARTY_DIR ] =
-                    array('file' => $smarty_dir, 'length' => strlen($smarty_dir),);
-            }
-        }
-        // walk the muted directories and test against $errfile
-        foreach (Smarty::$_muted_directories as $key => &$dir) {
-            if (!$dir) {
-                // resolve directory and length for speedy comparisons
-                $file = realpath($key);
-                if ($file === false) {
-                    // this directory does not exist, remove and skip it
-                    unset(Smarty::$_muted_directories[ $key ]);
-                    continue;
-                }
-                $dir = array('file' => $file, 'length' => strlen($file),);
-            }
-            if (!strncmp($errfile, $dir[ 'file' ], $dir[ 'length' ])) {
-                $_is_muted_directory = true;
-                break;
-            }
-        }
-        // pass to next error handler if this error did not occur inside SMARTY_DIR
-        // or the error was within smarty but masked to be ignored
-        if (!$_is_muted_directory || ($errno && $errno & error_reporting())) {
-            if (Smarty::$_previous_error_handler) {
-                return call_user_func(Smarty::$_previous_error_handler,
-                                      $errno,
-                                      $errstr,
-                                      $errfile,
-                                      $errline,
-                                      $errcontext);
-            } else {
-                return false;
-            }
-        }
-        return;
-    }
-
     /**
      * Enable error handler to mute expected messages
      *
      * @return void
+     * @deprecated
      */
     public static function muteExpectedErrors()
     {
-        /*
-            error muting is done because some people implemented custom error_handlers using
-            http://php.net/set_error_handler and for some reason did not understand the following paragraph:
-
-                It is important to remember that the standard PHP error handler is completely bypassed for the
-                error types specified by error_types unless the callback function returns FALSE.
-                error_reporting() settings will have no effect and your error handler will be called regardless -
-                however you are still able to read the current value of error_reporting and act appropriately.
-                Of particular note is that this value will be 0 if the statement that caused the error was
-                prepended by the @ error-control operator.
-
-            Smarty deliberately uses @filemtime() over file_exists() and filemtime() in some places. Reasons include
-                - @filemtime() is almost twice as fast as using an additional file_exists()
-                - between file_exists() and filemtime() a possible race condition is opened,
-                  which does not exist using the simple @filemtime() approach.
-        */
-        $error_handler = array('Smarty', 'mutingErrorHandler');
-        $previous = set_error_handler($error_handler);
-        // avoid dead loops
-        if ($previous !== $error_handler) {
-            Smarty::$_previous_error_handler = $previous;
-        }
+        return Smarty_Internal_ErrorHandler::muteExpectedErrors();
     }
 
     /**
      * Disable error handler muting expected messages
      *
-     * @return void
+     * @deprecated
      */
     public static function unmuteExpectedErrors()
     {
diff --git a/libs/sysplugins/smarty_internal_errorhandler.php b/libs/sysplugins/smarty_internal_errorhandler.php
new file mode 100644
index 00000000..96087720
--- /dev/null
+++ b/libs/sysplugins/smarty_internal_errorhandler.php
@@ -0,0 +1,112 @@
+<?php
+
+/**
+ * Smarty error handler
+ *
+ *
+ * @package    Smarty
+ * @subpackage PluginsInternal
+ * @author     Uwe Tews
+ *
+ * @deprecated
+Smarty does no longer use @filemtime()
+ */
+class Smarty_Internal_ErrorHandler
+{
+    /**
+     * contains directories outside of SMARTY_DIR that are to be muted by muteExpectedErrors()
+     */
+    public static $mutedDirectories = array();
+    /**
+     * error handler returned by set_error_handler() in self::muteExpectedErrors()
+     */
+    private static $previousErrorHandler = null;
+
+    /**
+     * Enable error handler to mute expected messages
+     *
+     * @return void
+     */
+    public static function muteExpectedErrors()
+    {
+        /*
+            error muting is done because some people implemented custom error_handlers using
+            http://php.net/set_error_handler and for some reason did not understand the following paragraph:
+
+                It is important to remember that the standard PHP error handler is completely bypassed for the
+                error types specified by error_types unless the callback function returns FALSE.
+                error_reporting() settings will have no effect and your error handler will be called regardless -
+                however you are still able to read the current value of error_reporting and act appropriately.
+                Of particular note is that this value will be 0 if the statement that caused the error was
+                prepended by the @ error-control operator.
+
+            Smarty deliberately uses @filemtime() over file_exists() and filemtime() in some places. Reasons include
+                - @filemtime() is almost twice as fast as using an additional file_exists()
+                - between file_exists() and filemtime() a possible race condition is opened,
+                  which does not exist using the simple @filemtime() approach.
+        */
+        $error_handler = array('Smarty_Internal_ErrorHandler', 'mutingErrorHandler');
+        $previous = set_error_handler($error_handler);
+        // avoid dead loops
+        if ($previous !== $error_handler) {
+            self::$previousErrorHandler = $previous;
+        }
+    }
+
+    /**
+     * Error Handler to mute expected messages
+     *
+     * @link http://php.net/set_error_handler
+     *
+     * @param  integer $errno Error level
+     * @param          $errstr
+     * @param          $errfile
+     * @param          $errline
+     * @param          $errcontext
+     *
+     * @return bool
+     */
+    public static function mutingErrorHandler($errno, $errstr, $errfile, $errline, $errcontext)
+    {
+        $_is_muted_directory = false;
+        // add the SMARTY_DIR to the list of muted directories
+        if (!isset(self::$mutedDirectories[ SMARTY_DIR ])) {
+            $smarty_dir = realpath(SMARTY_DIR);
+            if ($smarty_dir !== false) {
+                self::$mutedDirectories[ SMARTY_DIR ] =
+                    array('file' => $smarty_dir, 'length' => strlen($smarty_dir),);
+            }
+        }
+        // walk the muted directories and test against $errfile
+        foreach (self::$mutedDirectories as $key => &$dir) {
+            if (!$dir) {
+                // resolve directory and length for speedy comparisons
+                $file = realpath($key);
+                if ($file === false) {
+                    // this directory does not exist, remove and skip it
+                    unset(self::$mutedDirectories[ $key ]);
+                    continue;
+                }
+                $dir = array('file' => $file, 'length' => strlen($file),);
+            }
+            if (!strncmp($errfile, $dir[ 'file' ], $dir[ 'length' ])) {
+                $_is_muted_directory = true;
+                break;
+            }
+        }
+        // pass to next error handler if this error did not occur inside SMARTY_DIR
+        // or the error was within smarty but masked to be ignored
+        if (!$_is_muted_directory || ($errno && $errno & error_reporting())) {
+            if (self::$previousErrorHandler) {
+                return call_user_func(self::$previousErrorHandler,
+                                      $errno,
+                                      $errstr,
+                                      $errfile,
+                                      $errline,
+                                      $errcontext);
+            } else {
+                return false;
+            }
+        }
+    }
+}
\ No newline at end of file
diff --git a/libs/sysplugins/smarty_internal_testinstall.php b/libs/sysplugins/smarty_internal_testinstall.php
index 45963b79..7213b5d5 100644
--- a/libs/sysplugins/smarty_internal_testinstall.php
+++ b/libs/sysplugins/smarty_internal_testinstall.php
@@ -28,15 +28,12 @@ class Smarty_Internal_TestInstall
     public static function testInstall(Smarty $smarty, &$errors = null)
     {
         $status = true;
-
         if ($errors === null) {
             echo "<PRE>\n";
             echo "Smarty Installation test...\n";
             echo "Testing template directory...\n";
         }
-
         $_stream_resolve_include_path = function_exists('stream_resolve_include_path');
-
         // test if all registered template_dir are accessible
         foreach ($smarty->getTemplateDir() as $template_dir) {
             $_template_dir = $template_dir;
@@ -50,12 +47,10 @@ class Smarty_Internal_TestInstall
                     } else {
                         $template_dir = $smarty->ext->_getIncludePath->getIncludePath($_template_dir, null, $smarty);
                     }
-
                     if ($template_dir !== false) {
                         if ($errors === null) {
                             echo "$template_dir is OK.\n";
                         }
-
                         continue;
                     } else {
                         $status = false;
@@ -64,9 +59,8 @@ class Smarty_Internal_TestInstall
                         if ($errors === null) {
                             echo $message . ".\n";
                         } else {
-                            $errors['template_dir'] = $message;
+                            $errors[ 'template_dir' ] = $message;
                         }
-
                         continue;
                     }
                 } else {
@@ -75,20 +69,18 @@ class Smarty_Internal_TestInstall
                     if ($errors === null) {
                         echo $message . ".\n";
                     } else {
-                        $errors['template_dir'] = $message;
+                        $errors[ 'template_dir' ] = $message;
                     }
-
                     continue;
                 }
             }
-
             if (!is_dir($template_dir)) {
                 $status = false;
                 $message = "FAILED: $template_dir is not a directory";
                 if ($errors === null) {
                     echo $message . ".\n";
                 } else {
-                    $errors['template_dir'] = $message;
+                    $errors[ 'template_dir' ] = $message;
                 }
             } else if (!is_readable($template_dir)) {
                 $status = false;
@@ -96,7 +88,7 @@ class Smarty_Internal_TestInstall
                 if ($errors === null) {
                     echo $message . ".\n";
                 } else {
-                    $errors['template_dir'] = $message;
+                    $errors[ 'template_dir' ] = $message;
                 }
             } else {
                 if ($errors === null) {
@@ -104,11 +96,9 @@ class Smarty_Internal_TestInstall
                 }
             }
         }
-
         if ($errors === null) {
             echo "Testing compile directory...\n";
         }
-
         // test if registered compile_dir is accessible
         $__compile_dir = $smarty->getCompileDir();
         $_compile_dir = realpath($__compile_dir);
@@ -118,7 +108,7 @@ class Smarty_Internal_TestInstall
             if ($errors === null) {
                 echo $message . ".\n";
             } else {
-                $errors['compile_dir'] = $message;
+                $errors[ 'compile_dir' ] = $message;
             }
         } else if (!is_dir($_compile_dir)) {
             $status = false;
@@ -126,7 +116,7 @@ class Smarty_Internal_TestInstall
             if ($errors === null) {
                 echo $message . ".\n";
             } else {
-                $errors['compile_dir'] = $message;
+                $errors[ 'compile_dir' ] = $message;
             }
         } else if (!is_readable($_compile_dir)) {
             $status = false;
@@ -134,7 +124,7 @@ class Smarty_Internal_TestInstall
             if ($errors === null) {
                 echo $message . ".\n";
             } else {
-                $errors['compile_dir'] = $message;
+                $errors[ 'compile_dir' ] = $message;
             }
         } else if (!is_writable($_compile_dir)) {
             $status = false;
@@ -142,18 +132,16 @@ class Smarty_Internal_TestInstall
             if ($errors === null) {
                 echo $message . ".\n";
             } else {
-                $errors['compile_dir'] = $message;
+                $errors[ 'compile_dir' ] = $message;
             }
         } else {
             if ($errors === null) {
                 echo "{$_compile_dir} is OK.\n";
             }
         }
-
         if ($errors === null) {
             echo "Testing plugins directory...\n";
         }
-
         // test if all registered plugins_dir are accessible
         // and if core plugins directory is still registered
         $_core_plugins_dir = realpath(dirname(__FILE__) . '/../plugins');
@@ -170,12 +158,10 @@ class Smarty_Internal_TestInstall
                     } else {
                         $plugin_dir = $smarty->ext->_getIncludePath->getIncludePath($_plugin_dir, null, $smarty);
                     }
-
                     if ($plugin_dir !== false) {
                         if ($errors === null) {
                             echo "$plugin_dir is OK.\n";
                         }
-
                         continue;
                     } else {
                         $status = false;
@@ -183,9 +169,8 @@ class Smarty_Internal_TestInstall
                         if ($errors === null) {
                             echo $message . ".\n";
                         } else {
-                            $errors['plugins_dir'] = $message;
+                            $errors[ 'plugins_dir' ] = $message;
                         }
-
                         continue;
                     }
                 } else {
@@ -194,20 +179,18 @@ class Smarty_Internal_TestInstall
                     if ($errors === null) {
                         echo $message . ".\n";
                     } else {
-                        $errors['plugins_dir'] = $message;
+                        $errors[ 'plugins_dir' ] = $message;
                     }
-
                     continue;
                 }
             }
-
             if (!is_dir($plugin_dir)) {
                 $status = false;
                 $message = "FAILED: $plugin_dir is not a directory";
                 if ($errors === null) {
                     echo $message . ".\n";
                 } else {
-                    $errors['plugins_dir'] = $message;
+                    $errors[ 'plugins_dir' ] = $message;
                 }
             } else if (!is_readable($plugin_dir)) {
                 $status = false;
@@ -215,7 +198,7 @@ class Smarty_Internal_TestInstall
                 if ($errors === null) {
                     echo $message . ".\n";
                 } else {
-                    $errors['plugins_dir'] = $message;
+                    $errors[ 'plugins_dir' ] = $message;
                 }
             } else if ($_core_plugins_dir && $_core_plugins_dir == realpath($plugin_dir)) {
                 $_core_plugins_available = true;
@@ -233,15 +216,13 @@ class Smarty_Internal_TestInstall
             $message = "WARNING: Smarty's own libs/plugins is not available";
             if ($errors === null) {
                 echo $message . ".\n";
-            } else if (!isset($errors['plugins_dir'])) {
-                $errors['plugins_dir'] = $message;
+            } else if (!isset($errors[ 'plugins_dir' ])) {
+                $errors[ 'plugins_dir' ] = $message;
             }
         }
-
         if ($errors === null) {
             echo "Testing cache directory...\n";
         }
-
         // test if all registered cache_dir is accessible
         $__cache_dir = $smarty->getCacheDir();
         $_cache_dir = realpath($__cache_dir);
@@ -251,7 +232,7 @@ class Smarty_Internal_TestInstall
             if ($errors === null) {
                 echo $message . ".\n";
             } else {
-                $errors['cache_dir'] = $message;
+                $errors[ 'cache_dir' ] = $message;
             }
         } else if (!is_dir($_cache_dir)) {
             $status = false;
@@ -259,7 +240,7 @@ class Smarty_Internal_TestInstall
             if ($errors === null) {
                 echo $message . ".\n";
             } else {
-                $errors['cache_dir'] = $message;
+                $errors[ 'cache_dir' ] = $message;
             }
         } else if (!is_readable($_cache_dir)) {
             $status = false;
@@ -267,7 +248,7 @@ class Smarty_Internal_TestInstall
             if ($errors === null) {
                 echo $message . ".\n";
             } else {
-                $errors['cache_dir'] = $message;
+                $errors[ 'cache_dir' ] = $message;
             }
         } else if (!is_writable($_cache_dir)) {
             $status = false;
@@ -275,18 +256,16 @@ class Smarty_Internal_TestInstall
             if ($errors === null) {
                 echo $message . ".\n";
             } else {
-                $errors['cache_dir'] = $message;
+                $errors[ 'cache_dir' ] = $message;
             }
         } else {
             if ($errors === null) {
                 echo "{$_cache_dir} is OK.\n";
             }
         }
-
         if ($errors === null) {
             echo "Testing configs directory...\n";
         }
-
         // test if all registered config_dir are accessible
         foreach ($smarty->getConfigDir() as $config_dir) {
             $_config_dir = $config_dir;
@@ -299,12 +278,10 @@ class Smarty_Internal_TestInstall
                     } else {
                         $config_dir = $smarty->ext->_getIncludePath->getIncludePath($_config_dir, null, $smarty);
                     }
-
                     if ($config_dir !== false) {
                         if ($errors === null) {
                             echo "$config_dir is OK.\n";
                         }
-
                         continue;
                     } else {
                         $status = false;
@@ -312,9 +289,8 @@ class Smarty_Internal_TestInstall
                         if ($errors === null) {
                             echo $message . ".\n";
                         } else {
-                            $errors['config_dir'] = $message;
+                            $errors[ 'config_dir' ] = $message;
                         }
-
                         continue;
                     }
                 } else {
@@ -323,20 +299,18 @@ class Smarty_Internal_TestInstall
                     if ($errors === null) {
                         echo $message . ".\n";
                     } else {
-                        $errors['config_dir'] = $message;
+                        $errors[ 'config_dir' ] = $message;
                     }
-
                     continue;
                 }
             }
-
             if (!is_dir($config_dir)) {
                 $status = false;
                 $message = "FAILED: $config_dir is not a directory";
                 if ($errors === null) {
                     echo $message . ".\n";
                 } else {
-                    $errors['config_dir'] = $message;
+                    $errors[ 'config_dir' ] = $message;
                 }
             } else if (!is_readable($config_dir)) {
                 $status = false;
@@ -344,7 +318,7 @@ class Smarty_Internal_TestInstall
                 if ($errors === null) {
                     echo $message . ".\n";
                 } else {
-                    $errors['config_dir'] = $message;
+                    $errors[ 'config_dir' ] = $message;
                 }
             } else {
                 if ($errors === null) {
@@ -352,7 +326,6 @@ class Smarty_Internal_TestInstall
                 }
             }
         }
-
         if ($errors === null) {
             echo "Testing sysplugin files...\n";
         }
@@ -411,6 +384,7 @@ class Smarty_Internal_TestInstall
                 'smarty_internal_config_file_compiler.php'                  => true,
                 'smarty_internal_data.php'                                  => true,
                 'smarty_internal_debug.php'                                 => true,
+                'smarty_internal_errorhandler.php'                          => true,
                 'smarty_internal_extension_handler.php'                     => true,
                 'smarty_internal_method_addautoloadfilters.php'             => true,
                 'smarty_internal_method_adddefaultmodifiers.php'            => true,
@@ -524,7 +498,7 @@ class Smarty_Internal_TestInstall
                 if ($errors === null) {
                     echo $message . ".\n";
                 } else {
-                    $errors['sysplugins'] = $message;
+                    $errors[ 'sysplugins' ] = $message;
                 }
             } else if ($errors === null) {
                 echo "... OK\n";
@@ -535,10 +509,9 @@ class Smarty_Internal_TestInstall
             if ($errors === null) {
                 echo $message . ".\n";
             } else {
-                $errors['sysplugins_dir_constant'] = $message;
+                $errors[ 'sysplugins_dir_constant' ] = $message;
             }
         }
-
         if ($errors === null) {
             echo "Testing plugin files...\n";
         }
@@ -609,7 +582,7 @@ class Smarty_Internal_TestInstall
                 if ($errors === null) {
                     echo $message . ".\n";
                 } else {
-                    $errors['plugins'] = $message;
+                    $errors[ 'plugins' ] = $message;
                 }
             } else if ($errors === null) {
                 echo "... OK\n";
@@ -620,15 +593,13 @@ class Smarty_Internal_TestInstall
             if ($errors === null) {
                 echo $message . ".\n";
             } else {
-                $errors['plugins_dir_constant'] = $message;
+                $errors[ 'plugins_dir_constant' ] = $message;
             }
         }
-
         if ($errors === null) {
             echo "Tests complete.\n";
             echo "</PRE>\n";
         }
-
         return $status;
     }
 }