diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 2444c6f..3113d63 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -26,7 +26,7 @@ jobs:
           extensions: mbstring, intl, mysql, zlib, dom, openssl, soap, json, simplexml, libxml
 
       - name: checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       - name: Composer Install
         run: |
diff --git a/src/Signer.php b/src/Signer.php
index d6b4e44..a94066c 100755
--- a/src/Signer.php
+++ b/src/Signer.php
@@ -32,7 +32,7 @@
 
 class Signer
 {
-    const CANONICAL = [true,false,null,null];
+    const CANONICAL = [true, false, null, null];
 
     /**
      * Make Signature tag
@@ -74,7 +74,7 @@ public static function sign(
         if (empty($node) || empty($root)) {
             throw SignerException::tagNotFound($tagname);
         }
-        if (!self::existsSignature($content)) {
+        if (!self::existsSignature($content, $rootname)) {
             $dom = self::createSignature(
                 $certificate,
                 $dom,
@@ -174,6 +174,7 @@ private static function createSignature(
         $x509DataNode->appendChild($x509CertificateNode);
         return $dom;
     }
+
     /**
      * Remove old signature from document to replace it
      * @param string $content
@@ -196,6 +197,7 @@ public static function removeSignature($content)
         }
         return $dom->saveXML();
     }
+
     /**
      * Verify if xml signature is valid
      * @param string $content
@@ -218,9 +220,10 @@ public static function isSigned($content, $tagname = '', $canonical = self::CANO
     /**
      * Check if Signature tag already exists
      * @param string $content
+     * @param string|null $rootname
      * @return boolean
      */
-    public static function existsSignature($content)
+    public static function existsSignature($content, $rootname = null)
     {
         if (!Validator::isXML($content)) {
             throw SignerException::isNotXml();
@@ -229,8 +232,23 @@ public static function existsSignature($content)
         $dom->formatOutput = false;
         $dom->preserveWhiteSpace = false;
         $dom->loadXML($content);
-        $signature = $dom->getElementsByTagName('Signature')->item(0);
-        return !empty($signature);
+
+        if (empty($rootname)) {
+            return !empty($dom->getElementsByTagName('Signature')->item(0));
+        }
+
+        $root = $dom->documentElement->getElementsByTagName($rootname)->item(0);
+        if ($dom->documentElement->tagName == $rootname) {
+            $root = $dom->documentElement;
+        }
+
+        foreach ($root->childNodes as $child) {
+            if ($child->nodeName == 'Signature') {
+                return true;
+            }
+        }
+
+        return false;
     }
 
     /**
@@ -256,7 +274,7 @@ public static function signatureCheck($xml, $canonical = self::CANONICAL)
         $publicKey = PublicKey::createFromContent($certificateContent);
         $signInfoNode = self::canonize($signature->getElementsByTagName('SignedInfo')->item(0), $canonical);
         $signatureValue = $signature->getElementsByTagName('SignatureValue')->item(0)->nodeValue;
-        $decodedSignature = base64_decode(str_replace(array("\r", "\n"), '', $signatureValue));
+        $decodedSignature = base64_decode(str_replace(["\r", "\n"], '', $signatureValue));
         if (!$publicKey->verify($signInfoNode, $decodedSignature, $algorithm)) {
             throw SignerException::signatureComparisonFailed();
         }
@@ -285,7 +303,9 @@ public static function digestCheck($xml, $tagname = '', $canonical = self::CANON
                 $tagname = $root->nodeName;
             } else {
                 $xpath = new \DOMXPath($dom);
+                /** @var \DOMNodeList $entries */
                 $entries = $xpath->query('//@Id');
+                /** @var \DOMAttr $entry */
                 foreach ($entries as $entry) {
                     $tagname = $entry->ownerElement->nodeName;
                     break;
diff --git a/tests/SignerTest.php b/tests/SignerTest.php
index 655bc4b..524531b 100755
--- a/tests/SignerTest.php
+++ b/tests/SignerTest.php
@@ -23,6 +23,16 @@ public function testSign()
         $xmlsign = Signer::sign($certificate, $content, 'infNFe', 'Id');
         $actual = Signer::isSigned($xmlsign);
         $this->assertTrue($actual);
+
+        $xmlsign = Signer::sign($certificate, '<a><b><c>Teste Assinar mesmo documento 2x</c></b></a>', 'b', 'Id', OPENSSL_ALGO_SHA1, Signer::CANONICAL, 'b');
+        $this->assertTrue(Signer::existsSignature($xmlsign, 'b'));
+
+        $xmlsign2x = Signer::sign($certificate, $xmlsign, 'b', 'Id', OPENSSL_ALGO_SHA1, Signer::CANONICAL, 'a');
+        $this->assertTrue(Signer::existsSignature($xmlsign2x, 'a'));
+
+        $dom = new \DOMDocument('1.0', 'utf-8');
+        $dom->loadXML($xmlsign2x);
+        $this->assertEquals(2, $dom->getElementsByTagName('Signature')->count());
     }
 
     /**
@@ -79,6 +89,30 @@ public function testIsSignedFailDigest()
         Signer::isSigned($xml);
     }
 
+    public function testExistsSignatureRootnode(): void
+    {
+        $content = '<a><b><c></c><Signature></Signature></b></a>';
+        $this->assertTrue(Signer::existsSignature($content));
+
+        $content = '<a><b><c></c></b><Signature></Signature></a>';
+        $this->assertTrue(Signer::existsSignature($content));
+
+        $content = '<a><b><c></c><Signature></Signature></b></a>';
+        $this->assertFalse(Signer::existsSignature($content, 'a'));
+
+        $content = '<a><b><c></c></b><Signature></Signature></a>';
+        $this->assertTrue(Signer::existsSignature($content, 'a'));
+
+        $content = '<a><b><c></c><Signature></Signature></b></a>';
+        $this->assertFalse(Signer::existsSignature($content, 'c'));
+
+        $content = '<a><b><c><Signature></Signature></c></b></a>';
+        $this->assertTrue(Signer::existsSignature($content, 'c'));
+
+        $content = '<a><b><c></c><Signature></Signature></b></a>';
+        $this->assertTrue(Signer::existsSignature($content, 'b'));
+    }
+
     /**
      * @covers Signer::existsSignature
      * @covers Signer::digestCheck