diff --git a/src/Graze/Monolog/Processor/FilterProcessor.php b/src/Graze/Monolog/Processor/FilterProcessor.php
index eda3b04..ac7cd5a 100644
--- a/src/Graze/Monolog/Processor/FilterProcessor.php
+++ b/src/Graze/Monolog/Processor/FilterProcessor.php
@@ -52,7 +52,7 @@ public function __invoke(array $record)
      */
     protected function filterValue(&$value, $key)
     {
-        if (in_array($key, $this->keys)) {
+        if (in_array($key, $this->keys, true)) {
             $value = $this->replacement;
         }
     }
diff --git a/tests/unit/src/Graze/Monolog/Processor/FilterProcessorTest.php b/tests/unit/src/Graze/Monolog/Processor/FilterProcessorTest.php
index 1f46590..1d923ed 100644
--- a/tests/unit/src/Graze/Monolog/Processor/FilterProcessorTest.php
+++ b/tests/unit/src/Graze/Monolog/Processor/FilterProcessorTest.php
@@ -42,6 +42,7 @@ public function testProcessorIgnoresArrays()
 
         $this->assertEquals('YOU CAN\'T HANDLE THE TRUTH', $result['apples']);
         $this->assertInternalType('array', $result['oranges']);
+        $this->assertEquals([1,2,3], $result['oranges']);
     }
 
     public function testProcessorWorksWithNullReplacementValue()