diff --git a/src/Vies/Validator/ValidatorFR.php b/src/Vies/Validator/ValidatorFR.php
index 9385a5d..0a8e557 100644
--- a/src/Vies/Validator/ValidatorFR.php
+++ b/src/Vies/Validator/ValidatorFR.php
@@ -93,7 +93,7 @@ private function validateOld(string $vatNumber): string
             return "";
         }
         $checkVal .= "12";
-        if (PHP_INT_SIZE === 4 && function_exists("bcmod")) {
+        if (PHP_INT_SIZE === 4 && extension_loaded('bcmath')) {
             $checkVal = (int) bcmod($checkVal, "97");
         } else {
             $checkVal = intval($checkVal) % 97;
@@ -119,10 +119,10 @@ private function validateNew(string $vatNumber): bool
         $checkCharacter = array_flip(str_split($this->alphabet));
         $checkVal = ($checkCharacter[$vatNumber[0]] * $multiplier) + $checkCharacter[$vatNumber[1]] - $subStractor;
 
-        if (PHP_INT_SIZE === 4 && function_exists("bcmod")) {
+        if (PHP_INT_SIZE === 4 && extension_loaded("bcmath")) {
             return (int) bcmod(bcadd(substr($vatNumber, 2), strval(($checkVal / 11) + 1)), "11") === $checkVal % 11;
         } else {
-            return ((int)(intval(substr($vatNumber, 2)) + ($checkVal / 11) + 1) % 11) == $checkVal % 11;
+            return ((int) (intval(substr($vatNumber, 2)) + ($checkVal / 11) + 1) % 11) == $checkVal % 11;
         }
     }
 }
diff --git a/src/Vies/Validator/ValidatorNL.php b/src/Vies/Validator/ValidatorNL.php
index 92ceb96..f55f09a 100644
--- a/src/Vies/Validator/ValidatorNL.php
+++ b/src/Vies/Validator/ValidatorNL.php
@@ -130,7 +130,7 @@ protected function validateSoleProprietor(string $vatNumber): bool
             return $acc.$this->checkCharacter[$e];
         }, '2321');
 
-        if (PHP_INT_SIZE === 4 && function_exists('bcmod')) {
+        if (PHP_INT_SIZE === 4 && extension_loaded('bcmath')) {
             return bcmod($sumBase, '97') === '1';
         } else {
             return ((int) $sumBase % 97) === 1;
diff --git a/src/Vies/Validator/ValidatorSK.php b/src/Vies/Validator/ValidatorSK.php
index 9c3a048..da923dc 100644
--- a/src/Vies/Validator/ValidatorSK.php
+++ b/src/Vies/Validator/ValidatorSK.php
@@ -41,7 +41,7 @@ public function validate(string $vatNumber): bool
             return false;
         }
 
-        if (PHP_INT_SIZE === 4 && function_exists('bcmod')) {
+        if (PHP_INT_SIZE === 4 && extension_loaded("bcmath")) {
             return bcmod($vatNumber, '11') === '0';
         } else {
             return $vatNumber % 11 == 0;