diff --git a/src/Methods/Eth/BlockNumber.php b/src/Methods/Eth/BlockNumber.php
index f402239..7d6d33c 100644
--- a/src/Methods/Eth/BlockNumber.php
+++ b/src/Methods/Eth/BlockNumber.php
@@ -13,6 +13,7 @@ namespace Web3\Methods\Eth;
 
 use InvalidArgumentException;
 use Web3\Methods\EthMethod;
+use Web3\Formatters\BigNumberFormatter;
 
 class BlockNumber extends EthMethod
 {
@@ -35,7 +36,9 @@ class BlockNumber extends EthMethod
      * 
      * @var array
      */
-    protected $outputFormatters = [];
+    protected $outputFormatters = [
+        BigNumberFormatter::class
+    ];
 
     /**
      * defaultValues
diff --git a/test/unit/EthApiTest.php b/test/unit/EthApiTest.php
index b7c3959..7f30819 100644
--- a/test/unit/EthApiTest.php
+++ b/test/unit/EthApiTest.php
@@ -160,7 +160,7 @@ class EthApiTest extends TestCase
             if ($err !== null) {
                 return $this->fail($err->getMessage());
             }
-            $this->assertTrue(is_string($blockNumber));
+            $this->assertTrue(is_numeric($blockNumber->toString()));
         });
     }