diff --git a/src/FourOperations.php b/src/FourOperations.php
index c63ed325..d33762b3 100644
--- a/src/FourOperations.php
+++ b/src/FourOperations.php
@@ -1,44 +1,52 @@
 <?php
 namespace Laminas\Filter;
 
-
 use Laminas\Filter\AbstractFilter;
 use Laminas\Filter\Exception\InvalidArgumentException;
 
-class FourOperations extends AbstractFilter {
+class FourOperations extends AbstractFilter
+{
+
     const ADD = 'add';
+
     const SUB = 'sub';
+
     const MUL = 'mul';
+
     const DIV = 'div';
+
     const MOD = 'mod';
-    
+
     /**
      * $options expects an array with two keys:
      * operation: add, sub, mul or div
      * value: value of second operand
+     *
      * @param array $options
      */
     public function __construct(array $options)
     {
-        $operations = [self::ADD,self::SUB,self::MUL,self::DIV,self::MOD];
-        if (!isset($options['operation']) || (!in_array($options['operation'],$operations))){
-            throw new InvalidArgumentException(sprintf(
-                '%s expects argument operation string with one of theses values: add, sub, mul or div; received "%s"',
-                __METHOD__, (float) $options['operation']));
+        $operations = [
+            self::ADD,
+            self::SUB,
+            self::MUL,
+            self::DIV,
+            self::MOD
+        ];
+        if (! isset($options['operation']) || (! in_array($options['operation'], $operations))) {
+            throw new InvalidArgumentException(sprintf('%s expects argument operation string with one of theses values: add, sub, mul or div; received "%s"', __METHOD__, (float) $options['operation']));
         }
-        if (!isset($options['value'])){
-            throw new InvalidArgumentException(sprintf(
-                '%s expects argument value; received none',
-                __METHOD__));
+        if (! isset($options['value'])) {
+            throw new InvalidArgumentException(sprintf('%s expects argument value; received none', __METHOD__));
         }
         $this->options = $options;
     }
-    
+
     public function filter($value)
     {
         $value = (float) $value;
         $operand = (float) $this->options['value'];
-        switch ($this->options['operation']){
+        switch ($this->options['operation']) {
             case self::ADD:
                 return ($value + $operand);
             case self::SUB:
diff --git a/test/FourOperationsTest.php b/test/FourOperationsTest.php
index 4032e479..7ab95796 100644
--- a/test/FourOperationsTest.php
+++ b/test/FourOperationsTest.php
@@ -6,17 +6,33 @@
 
 class FourOperationsTest extends TestCase
 {
+
     public function testOperations(): void
     {
-        $filter = new FourOperations(['operation'=>'add','value'=>4]);
+        $filter = new FourOperations([
+            'operation' => 'add',
+            'value' => 4
+        ]);
         $this->assertEquals(9, $filter->filter(5));
-        $filter = new FourOperations(['operation'=>'sub','value'=>3]);
+        $filter = new FourOperations([
+            'operation' => 'sub',
+            'value' => 3
+        ]);
         $this->assertEquals(7, $filter->filter(10));
-        $filter = new FourOperations(['operation'=>'mul','value'=>5]);
+        $filter = new FourOperations([
+            'operation' => 'mul',
+            'value' => 5
+        ]);
         $this->assertEquals(30, $filter->filter(6));
-        $filter = new FourOperations(['operation'=>'div','value'=>12]);
+        $filter = new FourOperations([
+            'operation' => 'div',
+            'value' => 12
+        ]);
         $this->assertEquals(12, $filter->filter(144));
-        $filter = new FourOperations(['operation'=>'mod','value'=>2]);
+        $filter = new FourOperations([
+            'operation' => 'mod',
+            'value' => 2
+        ]);
         $this->assertEquals(1, $filter->filter(3));
     }
 }
\ No newline at end of file