diff --git a/.rector.php b/.rector.php
index d06fe0126fe..b6bb7ea9530 100644
--- a/.rector.php
+++ b/.rector.php
@@ -55,7 +55,6 @@
             CodeQuality\Expression\InlineIfToExplicitIfRector::class, # todo: TMP (!?!)
             CodeQuality\Expression\TernaryFalseExpressionToIfRector::class, # todo: TMP (!?!)
             CodeQuality\Foreach_\ForeachItemsAssignToEmptyArrayToAssignRector::class, # todo: TMP
-            CodeQuality\FuncCall\SimplifyRegexPatternRector::class, # todo: TMP
             CodeQuality\FunctionLike\SimplifyUselessVariableRector::class, # todo: TMP
             CodeQuality\Identical\SimplifyBoolIdenticalTrueRector::class, # todo: TMP
             CodeQuality\Identical\SimplifyConditionsRector::class, # todo: TMP
diff --git a/app/code/core/Mage/Adminhtml/Block/Widget/Grid/Column/Renderer/Abstract.php b/app/code/core/Mage/Adminhtml/Block/Widget/Grid/Column/Renderer/Abstract.php
index 0c03b09d115..100cce4d313 100644
--- a/app/code/core/Mage/Adminhtml/Block/Widget/Grid/Column/Renderer/Abstract.php
+++ b/app/code/core/Mage/Adminhtml/Block/Widget/Grid/Column/Renderer/Abstract.php
@@ -130,9 +130,9 @@ public function renderProperty()
 
         if ($this->getColumn()->hasData('width')) {
             $customWidth = $this->getColumn()->getData('width');
-            if (($customWidth === null) || (preg_match('/^[0-9]+%?$/', (string) $customWidth))) {
+            if (($customWidth === null) || (preg_match('/^\d+%?$/', (string) $customWidth))) {
                 $width = $customWidth;
-            } elseif (preg_match('/^([0-9]+)px$/', $customWidth, $matches)) {
+            } elseif (preg_match('/^(\d+)px$/', $customWidth, $matches)) {
                 $width = (int) $matches[1];
             }
         }
diff --git a/app/code/core/Mage/Adminhtml/controllers/RatingController.php b/app/code/core/Mage/Adminhtml/controllers/RatingController.php
index f2bc59acd73..8da47a4768d 100644
--- a/app/code/core/Mage/Adminhtml/controllers/RatingController.php
+++ b/app/code/core/Mage/Adminhtml/controllers/RatingController.php
@@ -85,7 +85,7 @@ public function saveAction()
                     $i = 1;
                     foreach ($options as $key => $optionCode) {
                         $optionModel = Mage::getModel('rating/rating_option');
-                        if (!preg_match('/^add_([0-9]*?)$/', $key)) {
+                        if (!preg_match('/^add_(\d*?)$/', $key)) {
                             $optionModel->setId($key);
                         }
 
diff --git a/app/code/core/Mage/Catalog/Helper/Product.php b/app/code/core/Mage/Catalog/Helper/Product.php
index 22099e9a83f..8b921b49dcf 100644
--- a/app/code/core/Mage/Catalog/Helper/Product.php
+++ b/app/code/core/Mage/Catalog/Helper/Product.php
@@ -443,7 +443,7 @@ public function getProduct($productId, $store, $identifierType = null)
 
         $expectedIdType = false;
         if ($identifierType === null) {
-            if (is_string($productId) && !preg_match('/^[+-]?[1-9][0-9]*$|^0$/', $productId)) {
+            if (is_string($productId) && !preg_match('/^[+-]?[1-9]\d*$|^0$/', $productId)) {
                 $expectedIdType = 'sku';
             }
         }
diff --git a/app/code/core/Mage/Catalog/Model/Product/Option/Type/File.php b/app/code/core/Mage/Catalog/Model/Product/Option/Type/File.php
index 4cc2864166f..7d0a91150b1 100644
--- a/app/code/core/Mage/Catalog/Model/Product/Option/Type/File.php
+++ b/app/code/core/Mage/Catalog/Model/Product/Option/Type/File.php
@@ -573,7 +573,7 @@ public function getEditableOptionValue($optionValue)
     public function parseOptionValue($optionValue, $productOptionValues)
     {
         // search quote item option Id in option value
-        if (preg_match('/\[([0-9]+)\]/', $optionValue, $matches)) {
+        if (preg_match('/\[(\d+)\]/', $optionValue, $matches)) {
             $confItemOptionId = $matches[1];
             $option = Mage::getModel('sales/quote_item_option')->load($confItemOptionId);
             try {
diff --git a/app/code/core/Mage/Checkout/Model/Resource/Agreement.php b/app/code/core/Mage/Checkout/Model/Resource/Agreement.php
index 008927d8f57..50e59c5e5af 100644
--- a/app/code/core/Mage/Checkout/Model/Resource/Agreement.php
+++ b/app/code/core/Mage/Checkout/Model/Resource/Agreement.php
@@ -32,7 +32,7 @@ protected function _beforeSave(Mage_Core_Model_Abstract $object)
         if (!$height) {
             $height = '';
         }
-        if ($height && preg_match('/[0-9]$/', $height)) {
+        if ($height && preg_match('/\d$/', $height)) {
             $height .= 'px';
         }
         $object->setContentHeight($height);
diff --git a/app/code/core/Mage/Cms/Model/Resource/Page.php b/app/code/core/Mage/Cms/Model/Resource/Page.php
index aa5a0897a0a..fe70583a913 100644
--- a/app/code/core/Mage/Cms/Model/Resource/Page.php
+++ b/app/code/core/Mage/Cms/Model/Resource/Page.php
@@ -265,7 +265,7 @@ public function getIsUniquePageToStores(Mage_Core_Model_Abstract $object)
      */
     protected function isNumericPageIdentifier(Mage_Core_Model_Abstract $object)
     {
-        return preg_match('/^[0-9]+$/', $object->getData('identifier'));
+        return preg_match('/^\d+$/', $object->getData('identifier'));
     }
 
     /**
diff --git a/app/code/core/Mage/Core/Model/Date.php b/app/code/core/Mage/Core/Model/Date.php
index 23546299ef7..92d04fc75f7 100644
--- a/app/code/core/Mage/Core/Model/Date.php
+++ b/app/code/core/Mage/Core/Model/Date.php
@@ -232,15 +232,15 @@ public function parseDateTime($dateTimeString, $dateTimeFormat)
         $formats = [
             // priority is important!
             '%m/%d/%y %I:%M' => [
-                '/^([0-9]{1,2})\/([0-9]{1,2})\/([0-9]{1,2}) ([0-9]{1,2}):([0-9]{1,2})/',
+                '/^(\d{1,2})\/(\d{1,2})\/(\d{1,2}) (\d{1,2}):(\d{1,2})/',
                 ['y' => 3, 'm' => 1, 'd' => 2, 'h' => 4, 'i' => 5],
             ],
             'm/d/y h:i' => [
-                '/^([0-9]{1,2})\/([0-9]{1,2})\/([0-9]{1,2}) ([0-9]{1,2}):([0-9]{1,2})/',
+                '/^(\d{1,2})\/(\d{1,2})\/(\d{1,2}) (\d{1,2}):(\d{1,2})/',
                 ['y' => 3, 'm' => 1, 'd' => 2, 'h' => 4, 'i' => 5],
             ],
-            '%m/%d/%y' => ['/^([0-9]{1,2})\/([0-9]{1,2})\/([0-9]{1,2})/', ['y' => 3, 'm' => 1, 'd' => 2]],
-            'm/d/y' => ['/^([0-9]{1,2})\/([0-9]{1,2})\/([0-9]{1,2})/', ['y' => 3, 'm' => 1, 'd' => 2]],
+            '%m/%d/%y' => ['/^(\d{1,2})\/(\d{1,2})\/(\d{1,2})/', ['y' => 3, 'm' => 1, 'd' => 2]],
+            'm/d/y' => ['/^(\d{1,2})\/(\d{1,2})\/(\d{1,2})/', ['y' => 3, 'm' => 1, 'd' => 2]],
         ];
 
         foreach ($formats as $supportedFormat => $regRule) {
diff --git a/app/code/core/Mage/Eav/Model/Entity/Attribute/Backend/Datetime.php b/app/code/core/Mage/Eav/Model/Entity/Attribute/Backend/Datetime.php
index d3128a0de52..8d521402438 100644
--- a/app/code/core/Mage/Eav/Model/Entity/Attribute/Backend/Datetime.php
+++ b/app/code/core/Mage/Eav/Model/Entity/Attribute/Backend/Datetime.php
@@ -59,7 +59,7 @@ public function formatDate($date)
             return null;
         }
         // unix timestamp given - simply instantiate date object
-        if (preg_match('/^[0-9]+$/', $date)) {
+        if (preg_match('/^\d+$/', $date)) {
             $date = new Zend_Date((int) $date);
         } elseif (preg_match('#^\d{4}-\d{2}-\d{2}( \d{2}:\d{2}:\d{2})?$#', $date)) {
             // international format
diff --git a/app/code/core/Mage/Payment/Model/Method/Cc.php b/app/code/core/Mage/Payment/Model/Method/Cc.php
index fd7bbb8713c..268508e21bd 100644
--- a/app/code/core/Mage/Payment/Model/Method/Cc.php
+++ b/app/code/core/Mage/Payment/Model/Method/Cc.php
@@ -100,11 +100,11 @@ public function validate()
                     // Solo only
                     'SO' => '/(^(6334)[5-9](\d{11}$|\d{13,14}$))|(^(6767)(\d{12}$|\d{14,15}$))/',
                     // Visa
-                    'VI'  => '/^4[0-9]{12}([0-9]{3})?$/',
+                    'VI'  => '/^4\d{12}(\d{3})?$/',
                     // Master Card
-                    'MC'  => '/^(5[1-5][0-9]{14}|2(22[1-9][0-9]{12}|2[3-9][0-9]{13}|[3-6][0-9]{14}|7[0-1][0-9]{13}|720[0-9]{12}))$/',
+                    'MC'  => '/^(5[1-5]\d{14}|2(22[1-9]\d{12}|2[3-9]\d{13}|[3-6]\d{14}|7[0-1]\d{13}|720\d{12}))$/',
                     // American Express
-                    'AE'  => '/^3[47][0-9]{13}$/',
+                    'AE'  => '/^3[47]\d{13}$/',
                     // Discover Network
                     'DI'  => $discoverNetworkRegexp,
                     // Dinners Club (Belongs to Discover Network)
@@ -177,15 +177,15 @@ public function hasVerification()
     public function getVerificationRegEx()
     {
         return [
-            'VI' => '/^[0-9]{3}$/', // Visa
-            'MC' => '/^[0-9]{3}$/',       // Master Card
-            'AE' => '/^[0-9]{4}$/',        // American Express
-            'DI' => '/^[0-9]{3}$/',          // Discovery
-            'SS' => '/^[0-9]{3,4}$/',
-            'SM' => '/^[0-9]{3,4}$/', // Switch or Maestro
-            'SO' => '/^[0-9]{3,4}$/', // Solo
-            'OT' => '/^[0-9]{3,4}$/',
-            'JCB' => '/^[0-9]{3,4}$/', //JCB
+            'VI' => '/^\d{3}$/', // Visa
+            'MC' => '/^\d{3}$/',       // Master Card
+            'AE' => '/^\d{4}$/',        // American Express
+            'DI' => '/^\d{3}$/',          // Discovery
+            'SS' => '/^\d{3,4}$/',
+            'SM' => '/^\d{3,4}$/', // Switch or Maestro
+            'SO' => '/^\d{3,4}$/', // Solo
+            'OT' => '/^\d{3,4}$/',
+            'JCB' => '/^\d{3,4}$/', //JCB
         ];
     }
 
diff --git a/lib/Varien/Data/Form/Element/Date.php b/lib/Varien/Data/Form/Element/Date.php
index 9e15728cdbe..a927acfef64 100644
--- a/lib/Varien/Data/Form/Element/Date.php
+++ b/lib/Varien/Data/Form/Element/Date.php
@@ -77,7 +77,7 @@ public function setValue($value, $format = null, $locale = null)
             $this->_value = $value;
             return $this;
         }
-        if (preg_match('/^[0-9]+$/', $value)) {
+        if (preg_match('/^\d+$/', $value)) {
             $this->_value = new Zend_Date($this->_toTimestamp($value));
             //$this->_value = new Zend_Date((int)value);
             return $this;