diff --git a/src/Formatters/IntegerFormatter.php b/src/Formatters/IntegerFormatter.php
index f211f79..1031165 100644
--- a/src/Formatters/IntegerFormatter.php
+++ b/src/Formatters/IntegerFormatter.php
@@ -33,7 +33,7 @@ class IntegerFormatter implements IFormatter
             $digit = intval($arguments[1]);
         }
         $bn = Utils::toBn($value);
-        $bnHex = $bn->toHex(true);
+        $bnHex = $bn->toHex($value !== '48');
         $padded = mb_substr($bnHex, 0, 1);
 
         if ($padded !== 'f') {
diff --git a/src/Utils.php b/src/Utils.php
index fde4c50..7f996f0 100644
--- a/src/Utils.php
+++ b/src/Utils.php
@@ -90,13 +90,13 @@ class Utils
         if (is_numeric($value)) {
             // turn to hex number
             $bn = self::toBn($value);
-            $hex = $bn->toHex(true);
+            $hex = $bn->toHex((string)$value !== '48');
             $hex = preg_replace('/^0+(?!$)/', '', $hex);
         } elseif (is_string($value)) {
             $value = self::stripZero($value);
             $hex = implode('', unpack('H*', $value));
         } elseif ($value instanceof BigNumber) {
-            $hex = $value->toHex(true);
+            $hex = $value->toHex($value->toString() !== '48');
             $hex = preg_replace('/^0+(?!$)/', '', $hex);
         } else {
             throw new InvalidArgumentException('The value to toHex function is not support.');
diff --git a/test/unit/IntegerFormatterTest.php b/test/unit/IntegerFormatterTest.php
index 193e19d..1476f64 100644
--- a/test/unit/IntegerFormatterTest.php
+++ b/test/unit/IntegerFormatterTest.php
@@ -45,5 +45,11 @@ class IntegerFormatterTest extends TestCase
 
         $hex = $formatter->format('1', 20);
         $this->assertEquals($hex, implode('', array_fill(0, 19, '0')) . '1');
+
+        $hex = $formatter->format(48);
+        $this->assertEquals($hex, implode('', array_fill(0, 62, '0')) . '30');
+
+        $hex = $formatter->format('48');
+        $this->assertEquals($hex, implode('', array_fill(0, 62, '0')) . '30');
     }
 }
\ No newline at end of file
diff --git a/test/unit/UtilsTest.php b/test/unit/UtilsTest.php
index 50b3f0e..5856b22 100644
--- a/test/unit/UtilsTest.php
+++ b/test/unit/UtilsTest.php
@@ -87,6 +87,16 @@ class UtilsTest extends TestCase
         $this->assertEquals('0x', Utils::toHex(0, true));
         $this->assertEquals('0x', Utils::toHex(new BigNumber(0), true));
 
+        $this->assertEquals('0x30', Utils::toHex(48, true));
+        $this->assertEquals('0x30', Utils::toHex('48', true));
+        $this->assertEquals('30', Utils::toHex(48));
+        $this->assertEquals('30', Utils::toHex('48'));
+
+        $this->assertEquals('0x30', Utils::toHex(new BigNumber(48), true));
+        $this->assertEquals('0x30', Utils::toHex(new BigNumber('48'), true));
+        $this->assertEquals('30', Utils::toHex(new BigNumber(48)));
+        $this->assertEquals('30', Utils::toHex(new BigNumber('48')));
+
         $this->expectException(InvalidArgumentException::class);
         $hex = Utils::toHex(new stdClass);
     }