diff --git a/NEWS b/NEWS
index ac82b47e..b8a83aef 100644
--- a/NEWS
+++ b/NEWS
@@ -1,3 +1,4 @@
+  - remove Smarty::_plugin_implementation_exists() - use is_callable() (messju)
   - ignore {strip}/{/strip) inside {strip}-blocks (messju)
   - fixed removal of leading/trailing newlines in {strip}-blocks (messju)
   - fixed proper escaping of " and ' with escape:javascript (messju)
diff --git a/libs/Smarty.class.php b/libs/Smarty.class.php
index 2310f203..7890e19c 100644
--- a/libs/Smarty.class.php
+++ b/libs/Smarty.class.php
@@ -1667,7 +1667,7 @@ class Smarty
         if (!$_return) {
             // see if we can get a template with the default template handler
             if (!empty($this->default_template_handler_func)) {
-                if (!$this->_plugin_implementation_exists($this->default_template_handler_func)) {
+                if (!is_callable($this->default_template_handler_func)) {
                     $this->trigger_error("default template handler function \"$this->default_template_handler_func\" doesn't exist.");
                 } else {
                     $_return = call_user_func_array(
@@ -1934,16 +1934,6 @@ class Smarty
         }
     }
 
-    /**
-     * check if the function or method exists
-     * @return bool
-     */
-    function _plugin_implementation_exists($function)
-    {
-        return (is_array($function)) ?
-            method_exists($function[0], $function[1]) || (in_array(strtolower($function[1]), (array)get_class_methods($function[0]))) : function_exists($function);
-    }
-
 
     /**
      * callback function for preg_replace, to call a non-cacheable block
diff --git a/libs/Smarty_Compiler.class.php b/libs/Smarty_Compiler.class.php
index f67ce799..97b091c4 100644
--- a/libs/Smarty_Compiler.class.php
+++ b/libs/Smarty_Compiler.class.php
@@ -250,7 +250,7 @@ class Smarty_Compiler extends Smarty {
         if (count($this->_plugins['prefilter']) > 0) {
             foreach ($this->_plugins['prefilter'] as $filter_name => $prefilter) {
                 if ($prefilter === false) continue;
-                if ($prefilter[3] || $this->_plugin_implementation_exists($prefilter[0])) {
+                if ($prefilter[3] || is_callable($prefilter[0])) {
                     $source_content = call_user_func_array($prefilter[0],
                                                             array($source_content, &$this));
                     $this->_plugins['prefilter'][$filter_name][3] = true;
@@ -360,7 +360,7 @@ class Smarty_Compiler extends Smarty {
         if (count($this->_plugins['postfilter']) > 0) {
             foreach ($this->_plugins['postfilter'] as $filter_name => $postfilter) {
                 if ($postfilter === false) continue;
-                if ($postfilter[3] || $this->_plugin_implementation_exists($postfilter[0])) {
+                if ($postfilter[3] || is_callable($postfilter[0])) {
                     $compiled_content = call_user_func_array($postfilter[0],
                                                               array($compiled_content, &$this));
                     $this->_plugins['postfilter'][$filter_name][3] = true;
@@ -571,7 +571,7 @@ class Smarty_Compiler extends Smarty {
         if (isset($this->_plugins['compiler'][$tag_command])) {
             $found = true;
             $plugin_func = $this->_plugins['compiler'][$tag_command][0];
-            if (!$this->_plugin_implementation_exists($plugin_func)) {
+            if (!is_callable($plugin_func)) {
                 $message = "compiler function '$tag_command' is not implemented";
                 $have_function = false;
             }
@@ -586,7 +586,7 @@ class Smarty_Compiler extends Smarty {
             include_once $plugin_file;
 
             $plugin_func = 'smarty_compiler_' . $tag_command;
-            if (!$this->_plugin_implementation_exists($plugin_func)) {
+            if (!is_callable($plugin_func)) {
                 $message = "plugin function $plugin_func() not found in $plugin_file\n";
                 $have_function = false;
             } else {
@@ -646,7 +646,7 @@ class Smarty_Compiler extends Smarty {
         if (isset($this->_plugins['block'][$tag_command])) {
             $found = true;
             $plugin_func = $this->_plugins['block'][$tag_command][0];
-            if (!$this->_plugin_implementation_exists($plugin_func)) {
+            if (!is_callable($plugin_func)) {
                 $message = "block function '$tag_command' is not implemented";
                 $have_function = false;
             }
diff --git a/libs/core/core.get_php_resource.php b/libs/core/core.get_php_resource.php
index 046f846e..b2f191bf 100644
--- a/libs/core/core.get_php_resource.php
+++ b/libs/core/core.get_php_resource.php
@@ -40,7 +40,7 @@ function smarty_core_get_php_resource(&$params, &$smarty)
         }
     } else if ($params['resource_type'] != 'file') {
 		$_template_source = null;
-        $_readable = $smarty->_plugin_implementation_exists($smarty->_plugins['resource'][$params['resource_type']][0][0])
+        $_readable = is_callable($smarty->_plugins['resource'][$params['resource_type']][0][0])
             && call_user_func_array($smarty->_plugins['resource'][$params['resource_type']][0][0],
                                     array($params['resource_name'], &$_template_source, &$smarty));
     }
diff --git a/libs/core/core.load_plugins.php b/libs/core/core.load_plugins.php
index 4f8f349f..2338e9bd 100644
--- a/libs/core/core.load_plugins.php
+++ b/libs/core/core.load_plugins.php
@@ -32,7 +32,7 @@ function smarty_core_load_plugins($params, &$smarty)
          */
         if (isset($_plugin)) {
             if (empty($_plugin[3])) {
-                if (!$smarty->_plugin_implementation_exists($_plugin[0])) {
+                if (!is_callable($_plugin[0])) {
                     $smarty->_trigger_fatal_error("[plugin] $_type '$_name' is not implemented", $_tpl_file, $_tpl_line, __FILE__, __LINE__);
                 } else {
                     $_plugin[1] = $_tpl_file;
diff --git a/libs/core/core.load_resource_plugin.php b/libs/core/core.load_resource_plugin.php
index 10ae1eaa..857d487b 100644
--- a/libs/core/core.load_resource_plugin.php
+++ b/libs/core/core.load_resource_plugin.php
@@ -27,7 +27,7 @@ function smarty_core_load_resource_plugin($params, &$smarty)
         if (!$_plugin[1] && count($_plugin[0])) {
             $_plugin[1] = true;
             foreach ($_plugin[0] as $_plugin_func) {                 
-                if (!$smarty->_plugin_implementation_exists($_plugin_func)) {
+                if (!is_callable($_plugin_func)) {
                     $_plugin[1] = false;
                     break;
                 }