diff --git a/src/RLP.php b/src/RLP.php
index 070b327..317c743 100644
--- a/src/RLP.php
+++ b/src/RLP.php
@@ -244,16 +244,25 @@ protected function padToEven(string $value)
      */
     protected function toBuffer($input)
     {
-        if (is_numeric($input)) {
-            $gmpInput = gmp_init($input, 10);
-            return new Buffer('0x' . gmp_strval($gmpInput, 16), 'hex');
-        } elseif (is_string($input)) {
+        if (is_string($input)) {
             if (strpos($input, '0x') === 0) {
                 // hex string
                 // $input = str_replace('0x', '', $input);
                 return new Buffer($input, 'hex');
             }
             return new Buffer(str_split($input, 1));
+        } elseif (is_numeric($input)) {
+            if (!$input || $input < 0) {
+                return new Buffer([]);
+            }
+            if (is_float($input)) {
+                $input = number_format($input, 0, '', '');
+                var_dump($input);
+            }
+            $gmpInput = gmp_init($input, 10);
+            return new Buffer('0x' . gmp_strval($gmpInput, 16), 'hex');
+        } elseif ($input === null) {
+            return new Buffer([]);
         } elseif (is_array($input)) {
             return new Buffer($input);
         } elseif ($input instanceof Buffer) {
diff --git a/test/unit/RLPTest.php b/test/unit/RLPTest.php
index 3159a6a..763bb56 100644
--- a/test/unit/RLPTest.php
+++ b/test/unit/RLPTest.php
@@ -67,6 +67,26 @@ public function testValidRlp()
         }
     }
 
+    /**
+     * testIssue14
+     * See: https://github.com/web3p/rlp/issues/14
+     * You can find test in: https://github.com/ethereum/wiki/wiki/RLP#examples
+     * 
+     * @return void
+     */
+    public function testIssue14()
+    {
+        $rlp = $this->rlp;
+        $this->assertEquals('c0', $rlp->encode([])->toString('hex'));
+        $this->assertEquals('80', $rlp->encode(0)->toString('hex'));
+        $this->assertEquals('80', $rlp->encode(0x0)->toString('hex'));
+        $this->assertEquals('80', $rlp->encode(-1)->toString('hex'));
+        $this->assertEquals('80', $rlp->encode(-2)->toString('hex'));
+        $this->assertEquals('30', $rlp->encode('0')->toString('hex'));
+        $this->assertEquals('00', $rlp->encode('0x0')->toString('hex'));
+        $this->assertEquals('80', $rlp->encode(null)->toString('hex'));
+    }
+
     /**
      * testInvalidRlp
      * Try to figure out what invalidrlptest.json is.