diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8a924ca3..80367524 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,6 +8,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Changed
 - Include docs and demo in the releases [#799](https://github.com/smarty-php/smarty/issues/799)
+- Using PHP functions as modifiers now triggers a deprecation notice because we will drop support for this in the next major release [#813](https://github.com/smarty-php/smarty/issues/813) 
 
 ### Fixed
 - Output buffer is now cleaned for internal PHP errors as well, not just for Exceptions [#514](https://github.com/smarty-php/smarty/issues/514)
diff --git a/libs/plugins/modifier.count.php b/libs/plugins/modifier.count.php
new file mode 100644
index 00000000..ca35fc11
--- /dev/null
+++ b/libs/plugins/modifier.count.php
@@ -0,0 +1,36 @@
+<?php
+/**
+ * Smarty plugin
+ *
+ * @package    Smarty
+ * @subpackage PluginsModifier
+ */
+/**
+ * Smarty count modifier plugin
+ * Type:     modifier
+ * Name:     count
+ * Purpose:  counts all elements in an array or in a Countable object
+ * Input:
+ *          - Countable|array: array or object to count
+ *          - mode: int defaults to 0 for normal count mode, if set to 1 counts recursive
+  *
+ * @param mixed $arrayOrObject  input array/object
+ * @param int $mode       count mode
+ *
+ * @return int
+ */
+function smarty_modifier_count($arrayOrObject, $mode = 0)
+{
+    /*
+     * @see https://www.php.net/count
+     * > Prior to PHP 8.0.0, if the parameter was neither an array nor an object that implements the Countable interface,
+     * > 1 would be returned, unless value was null, in which case 0 would be returned.
+     */
+
+    if ($arrayOrObject instanceof Countable || is_array($arrayOrObject)) {
+        return count($arrayOrObject, (int) $mode);
+    } elseif ($arrayOrObject === null) {
+        return 0;
+    }
+    return 1;
+}
diff --git a/libs/plugins/modifiercompiler.nl2br.php b/libs/plugins/modifiercompiler.nl2br.php
new file mode 100644
index 00000000..308c00e4
--- /dev/null
+++ b/libs/plugins/modifiercompiler.nl2br.php
@@ -0,0 +1,23 @@
+<?php
+
+/**
+ * Smarty plugin
+ *
+ * @package    Smarty
+ * @subpackage PluginsModifierCompiler
+ */
+/**
+ * Smarty nl2br modifier plugin
+ * Type:     modifier
+ * Name:     nl2br
+ * Purpose:  insert HTML line breaks before all newlines in a string
+ *
+ * @link   https://www.smarty.net/docs/en/language.modifier.nl2br.tpl nl2br (Smarty online manual)
+  *
+ * @param array $params parameters
+ *
+ * @return string with compiled code
+ */
+function smarty_modifiercompiler_nl2br($params) {
+    return 'nl2br((string) ' . $params[0] . ', (bool) ' . ($params[1] ?? true) . ')';
+}
diff --git a/libs/plugins/modifiercompiler.round.php b/libs/plugins/modifiercompiler.round.php
new file mode 100644
index 00000000..97f072f0
--- /dev/null
+++ b/libs/plugins/modifiercompiler.round.php
@@ -0,0 +1,23 @@
+<?php
+
+/**
+ * Smarty plugin
+ *
+ * @package    Smarty
+ * @subpackage PluginsModifierCompiler
+ */
+/**
+ * Smarty round modifier plugin
+ * Type:     modifier
+ * Name:     round
+ * Purpose:  Returns the rounded value of num to specified precision (number of digits after the decimal point)
+ *
+ * @link   https://www.smarty.net/docs/en/language.modifier.round.tpl round (Smarty online manual)
+  *
+ * @param array $params parameters
+ *
+ * @return string with compiled code
+ */
+function smarty_modifiercompiler_round($params) {
+    return 'round((float) ' . $params[0] . ', (int) ' . ($params[1] ?? 0) . ', (int) ' . ($params[2] ?? PHP_ROUND_HALF_UP) . ')';
+}
diff --git a/libs/plugins/modifiercompiler.str_repeat.php b/libs/plugins/modifiercompiler.str_repeat.php
new file mode 100644
index 00000000..18eb7a76
--- /dev/null
+++ b/libs/plugins/modifiercompiler.str_repeat.php
@@ -0,0 +1,23 @@
+<?php
+
+/**
+ * Smarty plugin
+ *
+ * @package    Smarty
+ * @subpackage PluginsModifierCompiler
+ */
+/**
+ * Smarty str_repeat modifier plugin
+ * Type:     modifier
+ * Name:     str_repeat
+ * Purpose:  returns string repeated times times
+ *
+ * @link   https://www.smarty.net/docs/en/language.modifier.str_repeat.tpl str_repeat (Smarty online manual)
+ *
+ * @param array $params parameters
+ *
+ * @return string with compiled code
+ */
+function smarty_modifiercompiler_str_repeat($params) {
+    return 'str_repeat((string) ' . $params[0] . ', (int) ' . $params[1] . ')';
+}
diff --git a/libs/plugins/modifiercompiler.strlen.php b/libs/plugins/modifiercompiler.strlen.php
new file mode 100644
index 00000000..d43e8ef1
--- /dev/null
+++ b/libs/plugins/modifiercompiler.strlen.php
@@ -0,0 +1,23 @@
+<?php
+
+/**
+ * Smarty plugin
+ *
+ * @package    Smarty
+ * @subpackage PluginsModifierCompiler
+ */
+/**
+ * Smarty strlen modifier plugin
+ * Type:     modifier
+ * Name:     strlen
+ * Purpose:  return the length of the given string
+ *
+ * @link   https://www.smarty.net/docs/en/language.modifier.strlen.tpl strlen (Smarty online manual)
+  *
+ * @param array $params parameters
+ *
+ * @return string with compiled code
+ */
+function smarty_modifiercompiler_strlen($params) {
+    return 'strlen((string) ' . $params[0] . ')';
+}
diff --git a/libs/sysplugins/smarty_internal_compile_private_modifier.php b/libs/sysplugins/smarty_internal_compile_private_modifier.php
index 72773fff..aea082f0 100644
--- a/libs/sysplugins/smarty_internal_compile_private_modifier.php
+++ b/libs/sysplugins/smarty_internal_compile_private_modifier.php
@@ -109,6 +109,9 @@ class Smarty_Internal_Compile_Private_Modifier extends Smarty_Internal_CompileBa
                             if (!is_object($compiler->smarty->security_policy)
                                 || $compiler->smarty->security_policy->isTrustedPhpModifier($modifier, $compiler)
                             ) {
+                                trigger_error('Using php-function "' . $modifier . '" as a modifier is deprecated and will be ' .
+                                    'removed in a future release. Use Smarty::registerPlugin to explicitly register ' .
+                                    'a custom modifier.', E_USER_DEPRECATED);
                                 $output = "{$modifier}({$params})";
                             }
                             $compiler->known_modifier_type[ $modifier ] = $type;
diff --git a/libs/sysplugins/smarty_security.php b/libs/sysplugins/smarty_security.php
index 3c29c813..42c2a766 100644
--- a/libs/sysplugins/smarty_security.php
+++ b/libs/sysplugins/smarty_security.php
@@ -105,7 +105,7 @@ class Smarty_Security
      *
      * @var array
      */
-    public $php_modifiers = array('escape', 'count', 'nl2br',);
+    public $php_modifiers = array('escape', 'count', 'sizeof', 'nl2br',);
 
     /**
      * This is an array of allowed tags.
@@ -328,7 +328,7 @@ class Smarty_Security
      *
      * @param string $modifier_name
      * @param object $compiler compiler object
-     *
+     * @deprecated
      * @return boolean                 true if modifier is trusted
      */
     public function isTrustedPhpModifier($modifier_name, $compiler)
diff --git a/tests/UnitTests/SecurityTests/SecurityTest.php b/tests/UnitTests/SecurityTests/SecurityTest.php
index d68ac3d4..60d80d67 100644
--- a/tests/UnitTests/SecurityTests/SecurityTest.php
+++ b/tests/UnitTests/SecurityTests/SecurityTest.php
@@ -52,7 +52,7 @@ class SecurityTest extends PHPUnit_Smarty
  */
     public function testTrustedPHPFunction()
     {
-        $this->assertEquals("5", $this->smarty->fetch('string:{assign var=foo value=[1,2,3,4,5]}{count($foo)}'));
+        $this->assertEquals("5", $this->smarty->fetch('string:{assign var=foo value=[1,2,3,4,5]}{sizeof($foo)}'));
     }
 
 /**
@@ -63,9 +63,9 @@ class SecurityTest extends PHPUnit_Smarty
     public function testNotTrustedPHPFunction()
     {
         $this->expectException('SmartyException');
-        $this->expectExceptionMessage('PHP function \'count\' not allowed by security setting');
+        $this->expectExceptionMessage('PHP function \'sizeof\' not allowed by security setting');
         $this->smarty->security_policy->php_functions = array('null');
-        $this->smarty->fetch('string:{assign var=foo value=[1,2,3,4,5]}{count($foo)}');
+        $this->smarty->fetch('string:{assign var=foo value=[1,2,3,4,5]}{sizeof($foo)}');
     }
 
 /**
@@ -75,38 +75,41 @@ class SecurityTest extends PHPUnit_Smarty
     {
         $this->smarty->security_policy->php_functions = array('null');
         $this->smarty->disableSecurity();
-        $this->assertEquals("5", $this->smarty->fetch('string:{assign var=foo value=[1,2,3,4,5]}{count($foo)}'));
+        $this->assertEquals("5", $this->smarty->fetch('string:{assign var=foo value=[1,2,3,4,5]}{sizeof($foo)}'));
     }
 
 /**
  * test trusted modifier
+ * @deprecated
  */
     public function testTrustedModifier()
     {
-        $this->assertEquals("5", $this->smarty->fetch('string:{assign var=foo value=[1,2,3,4,5]}{$foo|@count}'));
+        $this->assertEquals("5", @$this->smarty->fetch('string:{assign var=foo value=[1,2,3,4,5]}{$foo|@sizeof}'));
     }
 
 /**
  * test not trusted modifier
   * @runInSeparateProcess
   * @preserveGlobalState disabled
+ *  @deprecated
  */
     public function testNotTrustedModifier()
     {
         $this->expectException('SmartyException');
-        $this->expectExceptionMessage('modifier \'count\' not allowed by security setting');
+        $this->expectExceptionMessage('modifier \'sizeof\' not allowed by security setting');
         $this->smarty->security_policy->php_modifiers = array('null');
-        $this->smarty->fetch('string:{assign var=foo value=[1,2,3,4,5]}{$foo|@count}');
+        @$this->smarty->fetch('string:{assign var=foo value=[1,2,3,4,5]}{$foo|@sizeof}');
     }
 
 /**
  * test not trusted modifier at disabled security
+ * @deprecated
  */
     public function testDisabledTrustedModifier()
     {
         $this->smarty->security_policy->php_modifiers = array('null');
         $this->smarty->disableSecurity();
-        $this->assertEquals("5", $this->smarty->fetch('string:{assign var=foo value=[1,2,3,4,5]}{$foo|@count}'));
+        @$this->assertEquals("5", $this->smarty->fetch('string:{assign var=foo value=[1,2,3,4,5]}{$foo|@sizeof}'));
     }
 
 /**
diff --git a/tests/UnitTests/SmartyMethodsTests/RegisterBlock/RegisterBlockTest.php b/tests/UnitTests/SmartyMethodsTests/RegisterBlock/RegisterBlockTest.php
index 7d72c73d..b79ce9fa 100644
--- a/tests/UnitTests/SmartyMethodsTests/RegisterBlock/RegisterBlockTest.php
+++ b/tests/UnitTests/SmartyMethodsTests/RegisterBlock/RegisterBlockTest.php
@@ -40,14 +40,14 @@ class RegisterBlockTest extends PHPUnit_Smarty
     {
         $this->smarty->registerPlugin(Smarty::PLUGIN_BLOCK, 'testblock', 'myblock');
         $this->smarty->assign('value', 1);
-        $this->assertEquals(strtoupper('function hello world 1 1 function hello world 1 2 function hello world 1 3 '), $this->smarty->fetch('eval:{testblock}hello world {$value}{/testblock|strtoupper}'));
+        $this->assertEquals(strtoupper('function hello world 1 1 function hello world 1 2 function hello world 1 3 '), $this->smarty->fetch('eval:{testblock}hello world {$value}{/testblock|upper}'));
     }
 
     public function testRegisterBlockFunctionModifier2()
     {
         $this->smarty->registerPlugin(Smarty::PLUGIN_BLOCK, 'testblock', 'myblock');
         $this->smarty->assign('value', 1);
-        $this->assertEquals(strtoupper('function hello world 1 1 function hello world 1 2 function hello world 1 3 '), $this->smarty->fetch('eval:{testblock}hello world {$value}{/testblock|default:""|strtoupper}'));
+        $this->assertEquals(strtoupper('function hello world 1 1 function hello world 1 2 function hello world 1 3 '), $this->smarty->fetch('eval:{testblock}hello world {$value}{/testblock|default:""|upper}'));
     }
 
     public function testRegisterBlockFunctionWrapper()
diff --git a/tests/UnitTests/SmartyMethodsTests/RegisterObject/CompileRegisteredObjectFunctionTest.php b/tests/UnitTests/SmartyMethodsTests/RegisterObject/CompileRegisteredObjectFunctionTest.php
index 59bd3cb8..94a8ef55 100644
--- a/tests/UnitTests/SmartyMethodsTests/RegisterObject/CompileRegisteredObjectFunctionTest.php
+++ b/tests/UnitTests/SmartyMethodsTests/RegisterObject/CompileRegisteredObjectFunctionTest.php
@@ -60,13 +60,13 @@ class CompileRegisteredObjectFunctionTest extends PHPUnit_Smarty
 
     public function testRegisteredObjectBlockFunctionModifier1()
     {
-        $tpl = $this->smarty->createTemplate('eval:{objecttest->myblock}hello world{/objecttest->myblock|strtoupper}');
+        $tpl = $this->smarty->createTemplate('eval:{objecttest->myblock}hello world{/objecttest->myblock|upper}');
         $this->assertEquals(strtoupper('block test'), $this->smarty->fetch($tpl));
     }
 
     public function testRegisteredObjectBlockFunctionModifier2()
     {
-        $tpl = $this->smarty->createTemplate('eval:{objecttest->myblock}hello world{/objecttest->myblock|default:""|strtoupper}');
+        $tpl = $this->smarty->createTemplate('eval:{objecttest->myblock}hello world{/objecttest->myblock|default:""|upper}');
         $this->assertEquals(strtoupper('block test'), $this->smarty->fetch($tpl));
     }
     // TODO
diff --git a/tests/UnitTests/TemplateSource/TagTests/Append/CompileAppendTest.php b/tests/UnitTests/TemplateSource/TagTests/Append/CompileAppendTest.php
index 76b11052..9fab4fae 100644
--- a/tests/UnitTests/TemplateSource/TagTests/Append/CompileAppendTest.php
+++ b/tests/UnitTests/TemplateSource/TagTests/Append/CompileAppendTest.php
@@ -21,6 +21,7 @@ class CompileAppendTest extends PHPUnit_Smarty
         $this->smarty->addPluginsDir("../../../__shared/PHPunitplugins/");
         $this->smarty->addTemplateDir("../../../__shared/templates/");
         $this->smarty->addTemplateDir("./templates_tmp");
+        $this->smarty->registerPlugin('modifier', 'var_export', 'var_export');
     }
 
     public function testInit()
diff --git a/tests/UnitTests/TemplateSource/TagTests/Assign/CompileAssignTest.php b/tests/UnitTests/TemplateSource/TagTests/Assign/CompileAssignTest.php
index fefdd72d..fb02564f 100644
--- a/tests/UnitTests/TemplateSource/TagTests/Assign/CompileAssignTest.php
+++ b/tests/UnitTests/TemplateSource/TagTests/Assign/CompileAssignTest.php
@@ -21,6 +21,7 @@ class CompileAssignTest extends PHPUnit_Smarty
         $this->smarty->addPluginsDir("../../../__shared/PHPunitplugins/");
         $this->smarty->addTemplateDir("../../../__shared/templates/");
         $this->smarty->addTemplateDir("./templates_tmp");
+        $this->smarty->registerPlugin('modifier', 'var_export', 'var_export');
     }
 
     public function testInit()
diff --git a/tests/UnitTests/TemplateSource/TagTests/If/CompileIfTest.php b/tests/UnitTests/TemplateSource/TagTests/If/CompileIfTest.php
index 595ff55c..addd9999 100644
--- a/tests/UnitTests/TemplateSource/TagTests/If/CompileIfTest.php
+++ b/tests/UnitTests/TemplateSource/TagTests/If/CompileIfTest.php
@@ -21,6 +21,7 @@ class CompileIfTest extends PHPUnit_Smarty
         $this->smarty->addPluginsDir("../../../__shared/PHPunitplugins/");
         $this->smarty->addTemplateDir("../../../__shared/templates/");
         $this->smarty->addTemplateDir("./templates_tmp");
+        $this->smarty->registerPlugin('modifier', 'var_export', 'var_export');
     }
 
     public function testInit()
diff --git a/tests/UnitTests/TemplateSource/TagTests/PluginModifier/PluginModifierCountTest.php b/tests/UnitTests/TemplateSource/TagTests/PluginModifier/PluginModifierCountTest.php
new file mode 100644
index 00000000..c736356e
--- /dev/null
+++ b/tests/UnitTests/TemplateSource/TagTests/PluginModifier/PluginModifierCountTest.php
@@ -0,0 +1,48 @@
+<?php
+/**
+ * Smarty PHPunit tests of modifier
+ */
+
+/**
+ * class for modifier tests
+ *
+ * @runTestsInSeparateProcess
+ * @preserveGlobalState    disabled
+ * @backupStaticAttributes enabled
+ */
+class PluginModifierCountTest extends PHPUnit_Smarty
+{
+    public function setUp(): void
+    {
+        $this->setUpSmarty(dirname(__FILE__));
+    }
+
+    public function testArray()
+    {
+        $tpl = $this->smarty->createTemplate('string:count:{$v|count}');
+        $tpl->assign("v", array(1, 2, 3));
+        $this->assertEquals("count:3", $this->smarty->fetch($tpl));
+    }
+
+    public function testEmptyArray()
+    {
+        $tpl = $this->smarty->createTemplate('string:count:{$v|count}');
+        $tpl->assign("v", array());
+        $this->assertEquals("count:0", $this->smarty->fetch($tpl));
+    }
+
+    public function testNull()
+    {
+        $tpl = $this->smarty->createTemplate('string:count:{$v|count}');
+        $tpl->assign("v", null);
+        $this->assertEquals("count:0", $this->smarty->fetch($tpl));
+    }
+
+    public function testString()
+    {
+        $tpl = $this->smarty->createTemplate('string:count:{$v|count}');
+        $tpl->assign("v", "string");
+        $this->assertEquals("count:1", $this->smarty->fetch($tpl));
+    }
+
+}
diff --git a/tests/UnitTests/TemplateSource/TagTests/PluginModifier/PluginModifierExplodeTest.php b/tests/UnitTests/TemplateSource/TagTests/PluginModifier/PluginModifierExplodeTest.php
index b3b9d50e..5cd13dd3 100644
--- a/tests/UnitTests/TemplateSource/TagTests/PluginModifier/PluginModifierExplodeTest.php
+++ b/tests/UnitTests/TemplateSource/TagTests/PluginModifier/PluginModifierExplodeTest.php
@@ -14,6 +14,7 @@ class PluginModifierExplodeTest extends \PHPUnit_Smarty
     public function setUp(): void
     {
         $this->setUpSmarty(__DIR__);
+        $this->smarty->registerPlugin('modifier', 'json_encode', 'json_encode');
     }
 
     /**
diff --git a/tests/UnitTests/TemplateSource/TagTests/PluginModifier/PluginModifierNl2brTest.php b/tests/UnitTests/TemplateSource/TagTests/PluginModifier/PluginModifierNl2brTest.php
new file mode 100644
index 00000000..ed263019
--- /dev/null
+++ b/tests/UnitTests/TemplateSource/TagTests/PluginModifier/PluginModifierNl2brTest.php
@@ -0,0 +1,33 @@
+<?php
+/**
+ * Smarty PHPunit tests of modifier
+ */
+
+/**
+ * class for modifier tests
+ *
+ * @runTestsInSeparateProcess
+ * @preserveGlobalState    disabled
+ * @backupStaticAttributes enabled
+ */
+class PluginModifierNl2brTest extends PHPUnit_Smarty
+{
+    public function setUp(): void
+    {
+        $this->setUpSmarty(dirname(__FILE__));
+    }
+
+    public function testDefault()
+    {
+        $tpl = $this->smarty->createTemplate('string:{$v|nl2br}');
+        $tpl->assign("v", "Line1\nLine2");
+        $this->assertEquals("Line1<br />\nLine2", $this->smarty->fetch($tpl));
+    }
+
+    public function testNoXHTML()
+    {
+        $tpl = $this->smarty->createTemplate('string:{$v|nl2br:false}');
+        $tpl->assign("v", "Line1\nLine2");
+        $this->assertEquals("Line1<br>\nLine2", $this->smarty->fetch($tpl));
+    }
+}
diff --git a/tests/UnitTests/TemplateSource/TagTests/PluginModifier/PluginModifierStrRepeatTest.php b/tests/UnitTests/TemplateSource/TagTests/PluginModifier/PluginModifierStrRepeatTest.php
new file mode 100644
index 00000000..ef5bcfde
--- /dev/null
+++ b/tests/UnitTests/TemplateSource/TagTests/PluginModifier/PluginModifierStrRepeatTest.php
@@ -0,0 +1,33 @@
+<?php
+/**
+ * Smarty PHPunit tests of modifier
+ */
+
+/**
+ * class for modifier tests
+ *
+ * @runTestsInSeparateProcess
+ * @preserveGlobalState    disabled
+ * @backupStaticAttributes enabled
+ */
+class PluginModifierStrRepeatTest extends PHPUnit_Smarty
+{
+    public function setUp(): void
+    {
+        $this->setUpSmarty(dirname(__FILE__));
+    }
+
+    public function testDefault()
+    {
+        $tpl = $this->smarty->createTemplate('string:{$v|str_repeat:2}');
+        $tpl->assign("v", "foo");
+        $this->assertEquals("foofoo", $this->smarty->fetch($tpl));
+    }
+
+    public function testZeroTimes()
+    {
+        $tpl = $this->smarty->createTemplate('string:{$v|str_repeat:0}');
+        $tpl->assign("v", "foo");
+        $this->assertEquals("", $this->smarty->fetch($tpl));
+    }
+}
diff --git a/tests/UnitTests/TemplateSource/ValueTests/Math/MathTest.php b/tests/UnitTests/TemplateSource/ValueTests/Math/MathTest.php
index 3be6ad2e..b29d5beb 100644
--- a/tests/UnitTests/TemplateSource/ValueTests/Math/MathTest.php
+++ b/tests/UnitTests/TemplateSource/ValueTests/Math/MathTest.php
@@ -18,6 +18,7 @@ class MathTest extends PHPUnit_Smarty
     public function setUp(): void
     {
         $this->setUpSmarty(dirname(__FILE__));
+        $this->smarty->registerPlugin('modifier', 'sin', 'sin');
     }
 
     public function testInit()
@@ -104,7 +105,7 @@ class MathTest extends PHPUnit_Smarty
     {
         $this->smarty->disableSecurity();
         $expected = "22.00 -- 4.10";
-        $tpl = $this->smarty->createTemplate('eval:{$x = 4}{$y = 5.5}{$z = $x * $y}{"%0.2f"|sprintf:$z} -- {$x = 20.5}{$y = 5}{$z = $x / $y}{"%0.2f"|sprintf:$z}');
+        $tpl = $this->smarty->createTemplate('eval:{$x = 4}{$y = 5.5}{$z = $x * $y}{$z|string_format:"%0.2f"} -- {$x = 20.5}{$y = 5}{$z = $x / $y}{$z|string_format:"%0.2f"}');
         $this->assertEquals($expected, $this->smarty->fetch($tpl));
     }
 
@@ -120,7 +121,7 @@ class MathTest extends PHPUnit_Smarty
     {
         $this->smarty->disableSecurity();
         $expected = "22.00 -- 4.10";
-        $tpl = $this->smarty->createTemplate('eval:{$x = "4"}{$y = "5.5"}{$z = $x * $y}{"%0.2f"|sprintf:$z} -- {$x = "20.5"}{$y = "5"}{$z = $x / $y}{"%0.2f"|sprintf:$z}');
+        $tpl = $this->smarty->createTemplate('eval:{$x = "4"}{$y = "5.5"}{$z = $x * $y}{$z|string_format:"%0.2f"} -- {$x = "20.5"}{$y = "5"}{$z = $x / $y}{$z|string_format:"%0.2f"}');
         $this->assertEquals($expected, $this->smarty->fetch($tpl));
     }
 
@@ -132,36 +133,36 @@ class MathTest extends PHPUnit_Smarty
         $this->assertEquals($expected, $this->smarty->fetch($tpl));
     }
 
-	public function testBackticksIllegal()
-	{
-		$this->expectException(PHPUnit\Framework\Error\Warning::class);
-		$expected = "22.00";
-		$tpl = $this->smarty->createTemplate('eval:{$x = "4"}{$y = "5.5"}{math equation="`ls` x * y" x=$x y=$y}');
-		$this->assertEquals($expected, $this->smarty->fetch($tpl));
-	}
+    public function testBackticksIllegal()
+    {
+        $this->expectException(PHPUnit\Framework\Error\Warning::class);
+        $expected = "22.00";
+        $tpl = $this->smarty->createTemplate('eval:{$x = "4"}{$y = "5.5"}{math equation="`ls` x * y" x=$x y=$y}');
+        $this->assertEquals($expected, $this->smarty->fetch($tpl));
+    }
 
-	public function testDollarSignsIllegal()
-	{
-		$this->expectException(PHPUnit\Framework\Error\Warning::class);
-		$expected = "22.00";
-		$tpl = $this->smarty->createTemplate('eval:{$x = "4"}{$y = "5.5"}{math equation="$" x=$x y=$y}');
-		$this->assertEquals($expected, $this->smarty->fetch($tpl));
-	}
+    public function testDollarSignsIllegal()
+    {
+        $this->expectException(PHPUnit\Framework\Error\Warning::class);
+        $expected = "22.00";
+        $tpl = $this->smarty->createTemplate('eval:{$x = "4"}{$y = "5.5"}{math equation="$" x=$x y=$y}');
+        $this->assertEquals($expected, $this->smarty->fetch($tpl));
+    }
 
-	public function testBracketsIllegal()
-	{
-		$this->expectException(PHPUnit\Framework\Error\Warning::class);
-		$expected = "I";
-		$tpl = $this->smarty->createTemplate('eval:{$x = "0"}{$y = "1"}{math equation="((y/x).(x))[x]" x=$x y=$y}');
-		$this->assertEquals($expected, $this->smarty->fetch($tpl));
-	}
+    public function testBracketsIllegal()
+    {
+        $this->expectException(PHPUnit\Framework\Error\Warning::class);
+        $expected = "I";
+        $tpl = $this->smarty->createTemplate('eval:{$x = "0"}{$y = "1"}{math equation="((y/x).(x))[x]" x=$x y=$y}');
+        $this->assertEquals($expected, $this->smarty->fetch($tpl));
+    }
 
-	public function testRand()
-	{
-		$tpl = $this->smarty->createTemplate('eval:{$x = "0"}{math equation="x * rand()" x=$x}');
-		// this assertion may seem silly, but it serves to prove that using rand() without a parameter
-		// will not trigger a security error (see https://github.com/smarty-php/smarty/issues/794)
-		$this->assertEquals("0", $this->smarty->fetch($tpl));
-	}
+    public function testRand()
+    {
+        $tpl = $this->smarty->createTemplate('eval:{$x = "0"}{math equation="x * rand()" x=$x}');
+        // this assertion may seem silly, but it serves to prove that using rand() without a parameter
+        // will not trigger a security error (see https://github.com/smarty-php/smarty/issues/794)
+        $this->assertEquals("0", $this->smarty->fetch($tpl));
+    }
 
 }
diff --git a/tests/UnitTests/TemplateSource/_Issues/327/ModifierIssue327Test.php b/tests/UnitTests/TemplateSource/_Issues/327/ModifierIssue327Test.php
index 8418ea3e..0634907b 100644
--- a/tests/UnitTests/TemplateSource/_Issues/327/ModifierIssue327Test.php
+++ b/tests/UnitTests/TemplateSource/_Issues/327/ModifierIssue327Test.php
@@ -18,6 +18,7 @@ class ModifierIssue327Test extends PHPUnit_Smarty
     public function setUp(): void
     {
         $this->setUpSmarty(dirname(__FILE__));
+        $this->smarty->registerPlugin('modifier', 'substr', 'substr');
     }
 
     public function testInit()