diff --git a/src/validator-docs/Rules/Cnpj.php b/src/validator-docs/Rules/Cnpj.php
index a3e940a..4375204 100644
--- a/src/validator-docs/Rules/Cnpj.php
+++ b/src/validator-docs/Rules/Cnpj.php
@@ -4,39 +4,70 @@
 
 namespace geekcom\ValidatorDocs\Rules;
 
-use function mb_strlen;
 use function preg_match;
 
 final class Cnpj extends Sanitization
 {
+    private const CNPJ_BASE_LENGTH = 12;
+    private const REGEX_CNPJ_BASE = '/^[A-Z\d]{12}$/';
+    private const REGEX_CNPJ_FULL = '/^[A-Z\d]{12}\d{2}$/';
+    private const ASCII_ZERO = 48; // '0' in ASCII
+    private const ZEROED_CNPJ = '00000000000000';
+
+    // Weights from right to left: 2, 3, 4, 5, 6, 7, 8, 9, 2, 3, 4, 5 (for DV1)
+    // and 2, 3, 4, 5, 6, 7, 8, 9, 2, 3, 4, 5, 6 (for DV2)
+    private const DV1_WEIGHTS = [5, 4, 3, 2, 9, 8, 7, 6, 5, 4, 3, 2];
+    private const DV2_WEIGHTS = [6, 5, 4, 3, 2, 9, 8, 7, 6, 5, 4, 3, 2];
+
     public function validateCnpj($attribute, $value): bool
     {
-        $c = $this->sanitize($value);
+        $cnpjClean = strtoupper($this->sanitizeCNPJAlphanumeric($value));
+        if ($cnpjClean !== self::ZEROED_CNPJ && preg_match(self::REGEX_CNPJ_FULL, $cnpjClean)) {
+            $providedDV = substr($cnpjClean, self::CNPJ_BASE_LENGTH);
+            $calculatedDV = $this->calculateCNPJCheckDigits(substr($cnpjClean, 0, self::CNPJ_BASE_LENGTH));
 
-        if (mb_strlen($c) != 14 || preg_match("/^{$c[0]}{14}$/", $c)) {
-            return false;
+            return $providedDV === $calculatedDV;
         }
 
-        $b = [6, 5, 4, 3, 2, 9, 8, 7, 6, 5, 4, 3, 2];
+        return false;
+    }
 
-        for (
-            $i = 0, $n = 0; $i < 12; $n += $c[$i] * $b[++$i]
-        ) {
-        }
+    /**
+     * Calculate CNPJ check digits (DV) using the new alphanumeric rules.
+     */
+    public function calculateCNPJCheckDigits($cnpj): string
+    {
+        $cnpjClean = strtoupper($this->sanitizeCNPJAlphanumeric($cnpj));
+        if (preg_match(self::REGEX_CNPJ_BASE, $cnpjClean) && substr(self::ZEROED_CNPJ, 0, strlen($cnpjClean)) !== $cnpjClean) {
+            // Calculate DV1
+            $sumDV1 = 0;
+            for ($i = 0; $i < self::CNPJ_BASE_LENGTH; $i++) {
+                $charValue = ord($cnpjClean[$i]) - self::ASCII_ZERO;
+                $sumDV1 += $charValue * self::DV1_WEIGHTS[$i];
+            }
 
-        if ($c[12] != ((($n %= 11) < 2) ? 0 : 11 - $n)) {
-            return false;
-        }
+            $remainder1 = $sumDV1 % 11;
+            $dv1 = ($remainder1 < 2) ? 0 : 11 - $remainder1;
 
-        for (
-            $i = 0, $n = 0; $i <= 12; $n += $c[$i] * $b[$i++]
-        ) {
-        }
+            // Calculate DV2 (includes DV1 at the end)
+            $sumDV2 = 0;
+            for ($i = 0; $i < self::CNPJ_BASE_LENGTH; $i++) {
+                $charValue = ord($cnpjClean[$i]) - self::ASCII_ZERO;
+                $sumDV2 += $charValue * self::DV2_WEIGHTS[$i];
+            }
+            $sumDV2 += $dv1 * self::DV2_WEIGHTS[self::CNPJ_BASE_LENGTH];
+
+            $remainder2 = $sumDV2 % 11;
+            $dv2 = ($remainder2 < 2) ? 0 : 11 - $remainder2;
 
-        if ($c[13] != ((($n %= 11) < 2) ? 0 : 11 - $n)) {
-            return false;
+            return "{$dv1}{$dv2}";
         }
 
-        return true;
+        throw new \InvalidArgumentException('Invalid CNPJ');
+    }
+
+    private function sanitizeCNPJAlphanumeric(string $value): string
+    {
+        return preg_replace('/[.\-\/]/', '', strtoupper(trim($value)));
     }
 }
diff --git a/tests/TestValidator.php b/tests/TestValidator.php
index 2a870b4..7f92453 100644
--- a/tests/TestValidator.php
+++ b/tests/TestValidator.php
@@ -24,22 +24,35 @@ public function cpf()
         $this->assertTrue($incorrect->fails());
     }
 
-    /** @test **/
-    public function cnpj()
+    /**
+     * @test
+     * @dataProvider cnpjDataProvider
+     **/
+    public function cnpj(string $cnpj, bool $expected): void
     {
-        $correct = Validator::make(
-            ['certo' => '53.084.587/0001-20'],
-            ['certo' => 'cnpj']
-        );
-
-        $incorrect = Validator::make(
-            ['errado' => '51.084.587/0001-20'],
-            ['errado' => 'cnpj']
-        );
+        $valid = Validator::make(['cnpj_attribute' => $cnpj], ['cnpj_attribute' => 'cnpj'])->passes();
 
-        $this->assertTrue($correct->passes());
+        $this->assertSame($expected, $valid);
+    }
 
-        $this->assertTrue($incorrect->fails());
+    public function cnpjDataProvider(): array
+    {
+        return [
+            'Alphanumeric CNPJ with dots and dashes 1'   => ['T6.JSP.XPS/0001-11', true],
+            'Alphanumeric CNPJ with dots and dashes 2'   => ['T6.JSP.XPS/J84K-69', true],
+            'Alphanumeric CNPJ with dots and dashes 3'   => ['D2.M97.AA0/0001-63', true],
+            'Alphanumeric CNPJ with dots and dashes 4'   => ['W9.7VY.JMY/0001-81', true],
+            'Alphanumeric CNPJ clean 1'                  => ['E5SGVHX9000190', true],
+            'Alphanumeric CNPJ clean 2'                  => ['E5SGVHX960LR53', true],
+            'Alphanumeric CNPJ clean 3'                  => ['12ABC34501DE35', true],
+            'Numeric CNPJ with dots and dashes 1'        => ['32.332.643/0001-29', true],
+            'Numeric CNPJ with dots and dashes 2'        => ['32.332.643/3060-40', true],
+            'Numeric CNPJ clean 1'                       => ['38725833000192', true],
+            'Numeric CNPJ clean 2'                       => ['38725833223060', true],
+            'Invalid CNPJ'                               => ['12.345.678/0001-00', false],
+            'Zeroed CNPJ'                                => ['00.000.000/0000-00', false],
+            'CNPJ with invalid characters'               => ['32.332.643/0001-9!', false],
+        ];
     }
 
     /** @test **/