diff --git a/libs/plugins/function.math.php b/libs/plugins/function.math.php
index fd5b3d16..8560e944 100644
--- a/libs/plugins/function.math.php
+++ b/libs/plugins/function.math.php
@@ -69,7 +69,7 @@ function smarty_function_math($params, $template)
     // Adapted from https://www.php.net/manual/en/function.eval.php#107377
     $number = '(?:\d+(?:[,.]\d+)?|pi|π)'; // What is a number
     $functionsOrVars = '((?:0x[a-fA-F0-9]+)|([a-zA-Z_\x7f-\xff][a-zA-Z0-9_\x7f-\xff]*))';
-    $operators = '[+\/*\^%-]'; // Allowed math operators
+    $operators = '[,+\/*\^%-]'; // Allowed math operators
     $regexp = '/^(('.$number.'|'.$functionsOrVars.'|('.$functionsOrVars.'\s*\((?1)+\)|\((?1)+\)))(?:'.$operators.'(?1))?)+$/';
 
     if (!preg_match($regexp, $equation)) {
diff --git a/tests/UnitTests/TemplateSource/ValueTests/Math/MathTest.php b/tests/UnitTests/TemplateSource/ValueTests/Math/MathTest.php
index 645c0a40..82255644 100644
--- a/tests/UnitTests/TemplateSource/ValueTests/Math/MathTest.php
+++ b/tests/UnitTests/TemplateSource/ValueTests/Math/MathTest.php
@@ -52,6 +52,22 @@ class MathTest extends PHPUnit_Smarty
         $this->assertEquals($expected, $this->smarty->fetch($tpl));
     }
 
+    public function testMathMaxFunctionParameters()
+    {
+        $this->smarty->disableSecurity();
+        $expected = max(0, 2) . ' -- ' . max(0, 2, 3);
+        $tpl = $this->smarty->createTemplate('eval:{$x = 0}{$y = 2}{$z = 3}{math equation="max(x, y)" x=$x y=$y} -- {math equation="max(x, y, z)" x=$x y=$y z=$z}');
+        $this->assertEquals($expected, $this->smarty->fetch($tpl));
+    }
+
+    public function testMathMinFunctionParameters()
+    {
+        $this->smarty->disableSecurity();
+        $expected = min(1, 2) . ' -- ' . min(1, 2, 0);
+        $tpl = $this->smarty->createTemplate('eval:{$x = 1}{$y = 2}{$z = 0}{math equation="min(x, y)" x=$x y=$y} -- {math equation="min(x, y, z)" x=$x y=$y z=$z}');
+        $this->assertEquals($expected, $this->smarty->fetch($tpl));
+    }
+
     public function testSyntaxSin()
     {
         $this->smarty->disableSecurity();