diff --git a/src/PhpSpreadsheet/Calculation/Calculation.php b/src/PhpSpreadsheet/Calculation/Calculation.php
index b3665abd..a5d40d01 100644
--- a/src/PhpSpreadsheet/Calculation/Calculation.php
+++ b/src/PhpSpreadsheet/Calculation/Calculation.php
@@ -2360,10 +2360,10 @@ class Calculation
         if (self::$functionReplaceFromExcel === null) {
             self::$functionReplaceFromExcel = [];
             foreach (array_keys(self::$localeFunctions) as $excelFunctionName) {
-                self::$functionReplaceFromExcel[] = '/(@?[^\w\.])' . preg_quote($excelFunctionName) . '([\s]*\()/Ui';
+                self::$functionReplaceFromExcel[] = '/(@?[^\w\.])' . preg_quote($excelFunctionName, '/') . '([\s]*\()/Ui';
             }
             foreach (array_keys(self::$localeBoolean) as $excelBoolean) {
-                self::$functionReplaceFromExcel[] = '/(@?[^\w\.])' . preg_quote($excelBoolean) . '([^\w\.])/Ui';
+                self::$functionReplaceFromExcel[] = '/(@?[^\w\.])' . preg_quote($excelBoolean, '/') . '([^\w\.])/Ui';
             }
         }
 
@@ -2388,10 +2388,10 @@ class Calculation
         if (self::$functionReplaceFromLocale === null) {
             self::$functionReplaceFromLocale = [];
             foreach (array_values(self::$localeFunctions) as $localeFunctionName) {
-                self::$functionReplaceFromLocale[] = '/(@?[^\w\.])' . preg_quote($localeFunctionName) . '([\s]*\()/Ui';
+                self::$functionReplaceFromLocale[] = '/(@?[^\w\.])' . preg_quote($localeFunctionName, '/') . '([\s]*\()/Ui';
             }
             foreach (array_values(self::$localeBoolean) as $excelBoolean) {
-                self::$functionReplaceFromLocale[] = '/(@?[^\w\.])' . preg_quote($excelBoolean) . '([^\w\.])/Ui';
+                self::$functionReplaceFromLocale[] = '/(@?[^\w\.])' . preg_quote($excelBoolean, '/') . '([^\w\.])/Ui';
             }
         }
 
diff --git a/src/PhpSpreadsheet/Cell/AdvancedValueBinder.php b/src/PhpSpreadsheet/Cell/AdvancedValueBinder.php
index 9ee5445c..c4ac77f1 100644
--- a/src/PhpSpreadsheet/Cell/AdvancedValueBinder.php
+++ b/src/PhpSpreadsheet/Cell/AdvancedValueBinder.php
@@ -91,7 +91,7 @@ class AdvancedValueBinder extends DefaultValueBinder implements IValueBinder
             $currencyCode = StringHelper::getCurrencyCode();
             $decimalSeparator = StringHelper::getDecimalSeparator();
             $thousandsSeparator = StringHelper::getThousandsSeparator();
-            if (preg_match('/^' . preg_quote($currencyCode) . ' *(\d{1,3}(' . preg_quote($thousandsSeparator) . '\d{3})*|(\d+))(' . preg_quote($decimalSeparator) . '\d{2})?$/', $value)) {
+            if (preg_match('/^' . preg_quote($currencyCode, '/') . ' *(\d{1,3}(' . preg_quote($thousandsSeparator, '/') . '\d{3})*|(\d+))(' . preg_quote($decimalSeparator, '/') . '\d{2})?$/', $value)) {
                 // Convert value to number
                 $value = (float) trim(str_replace([$currencyCode, $thousandsSeparator, $decimalSeparator], ['', '', '.'], $value));
                 $cell->setValueExplicit($value, DataType::TYPE_NUMERIC);
diff --git a/src/PhpSpreadsheet/ReferenceHelper.php b/src/PhpSpreadsheet/ReferenceHelper.php
index 3ccdba0c..bd74f0f1 100644
--- a/src/PhpSpreadsheet/ReferenceHelper.php
+++ b/src/PhpSpreadsheet/ReferenceHelper.php
@@ -654,8 +654,8 @@ class ReferenceHelper
                                 $row = 10000000 + trim($match[3], '$');
                                 $cellIndex = $column . $row;
 
-                                $newCellTokens[$cellIndex] = preg_quote($toString);
-                                $cellTokens[$cellIndex] = '/(?<!\d\$\!)' . preg_quote($fromString) . '(?!\d)/i';
+                                $newCellTokens[$cellIndex] = preg_quote($toString, '/');
+                                $cellTokens[$cellIndex] = '/(?<!\d\$\!)' . preg_quote($fromString, '/') . '(?!\d)/i';
                                 ++$adjustCount;
                             }
                         }
@@ -679,8 +679,8 @@ class ReferenceHelper
                                 $row = 10000000;
                                 $cellIndex = $column . $row;
 
-                                $newCellTokens[$cellIndex] = preg_quote($toString);
-                                $cellTokens[$cellIndex] = '/(?<![A-Z\$\!])' . preg_quote($fromString) . '(?![A-Z])/i';
+                                $newCellTokens[$cellIndex] = preg_quote($toString, '/');
+                                $cellTokens[$cellIndex] = '/(?<![A-Z\$\!])' . preg_quote($fromString, '/') . '(?![A-Z])/i';
                                 ++$adjustCount;
                             }
                         }
@@ -705,8 +705,8 @@ class ReferenceHelper
                                 $row = trim($row, '$') + 10000000;
                                 $cellIndex = $column . $row;
 
-                                $newCellTokens[$cellIndex] = preg_quote($toString);
-                                $cellTokens[$cellIndex] = '/(?<![A-Z]\$\!)' . preg_quote($fromString) . '(?!\d)/i';
+                                $newCellTokens[$cellIndex] = preg_quote($toString, '/');
+                                $cellTokens[$cellIndex] = '/(?<![A-Z]\$\!)' . preg_quote($fromString, '/') . '(?!\d)/i';
                                 ++$adjustCount;
                             }
                         }
@@ -731,8 +731,8 @@ class ReferenceHelper
                                 $row = trim($row, '$') + 10000000;
                                 $cellIndex = $row . $column;
 
-                                $newCellTokens[$cellIndex] = preg_quote($toString);
-                                $cellTokens[$cellIndex] = '/(?<![A-Z\$\!])' . preg_quote($fromString) . '(?!\d)/i';
+                                $newCellTokens[$cellIndex] = preg_quote($toString, '/');
+                                $cellTokens[$cellIndex] = '/(?<![A-Z\$\!])' . preg_quote($fromString, '/') . '(?!\d)/i';
                                 ++$adjustCount;
                             }
                         }