diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index f917cea..93d3cc9 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -16,7 +16,7 @@ jobs:
       fail-fast: false
       matrix:
         operating-system: [ubuntu-latest]
-        php-versions: ['8.1', '8.2', '8.3']
+        php-versions: ['8.1', '8.2', '8.3', '8.4']
 
     steps:
       - name: Checkout
diff --git a/src/GoogleAuthenticator.php b/src/GoogleAuthenticator.php
index a07df85..4d5752d 100644
--- a/src/GoogleAuthenticator.php
+++ b/src/GoogleAuthenticator.php
@@ -25,8 +25,6 @@ class GoogleAuthenticator
      * Create new secret.
      * 16 characters, randomly chosen from the allowed base32 characters.
      *
-     * @param int $secretLength
-     * @return string
      * @throws Exception
      */
     public function createSecret(int $secretLength = 16) : string
@@ -53,12 +51,9 @@ public function createSecret(int $secretLength = 16) : string
     /**
      * Calculate the code, with given secret and point in time
      *
-     * @param string $secret
-     * @param int|null $timeSlice
-     * @return string
      * @throws Exception
      */
-    public function getCode(string $secret, int $timeSlice = null) : string
+    public function getCode(string $secret, ?int $timeSlice = null) : string
     {
         if ($timeSlice === null) {
             $timeSlice = floor(time() / 30);
@@ -78,7 +73,7 @@ public function getCode(string $secret, int $timeSlice = null) : string
         // grab 4 bytes of the result
         $hashpart = substr($hm, $offset, 4);
 
-        // Unpak binary value
+        // Unpack binary value
         $value = unpack('N', $hashpart);
         $value = $value[1];
         // Only 32 bits
@@ -110,8 +105,6 @@ public function getQRCodeUrl(string $account, string $secret, ?string $issuer =
 
     /**
      * Build an OTP URI using the builder pattern
-     *
-     * @return UriBuilder
      */
     public function getUriBuilder(): UriBuilder
     {
@@ -143,10 +136,7 @@ protected function getQRCodeDataUri(string $uri) : string
     /**
      * Check if the code is correct. This will accept codes starting from $discrepancy*30sec ago to $discrepancy*30sec from now
      *
-     * @param string $secret
-     * @param string $code
      * @param int $discrepancy This is the allowed time drift in 30 second units (8 means 4 minutes before or after)
-     * @return bool
      */
     public function verifyCode(string $secret, string $code, int $discrepancy = 1) : bool
     {
@@ -173,9 +163,6 @@ public function verifyCode(string $secret, string $code, int $discrepancy = 1) :
 
     /**
      * Set the code length, should be >=6
-     *
-     * @param int $length
-     * @return self
      */
     public function setCodeLength(int $length) : self
     {
diff --git a/src/OtpAuth/Base32.php b/src/OtpAuth/Base32.php
index fbc9ab7..fcc4d71 100644
--- a/src/OtpAuth/Base32.php
+++ b/src/OtpAuth/Base32.php
@@ -14,12 +14,8 @@ class Base32
 
     /**
      * Helper method to encode base32
-     *
-     * @param string $data
-     * @param $length
-     * @return string
      */
-    public static function encode(string $data, $length = null): string
+    public static function encode(string $data, ?int $length = null): string
     {
         $length ??= strlen($data);
         $encoded = '';
@@ -31,14 +27,11 @@ public static function encode(string $data, $length = null): string
 
     /**
      * Helper method to decode base32
-     *
-     * @param string $data
-     * @return ?string The decoded string, or null on error
      */
     public static function decode(string $data): ?string
     {
         if (empty($data)) {
-            return '';
+            return null;
         }
 
         $base32charsFlipped = array_flip(self::CHARS);
@@ -77,4 +70,4 @@ public static function decode(string $data): ?string
 
         return $binaryString;
     }
-}
\ No newline at end of file
+}
diff --git a/src/OtpAuth/Paramters/Algorithm.php b/src/OtpAuth/Parameters/Algorithm.php
similarity index 73%
rename from src/OtpAuth/Paramters/Algorithm.php
rename to src/OtpAuth/Parameters/Algorithm.php
index 5991719..cd092a6 100644
--- a/src/OtpAuth/Paramters/Algorithm.php
+++ b/src/OtpAuth/Parameters/Algorithm.php
@@ -1,6 +1,6 @@
 <?php
 
-namespace Vectorface\OtpAuth\Paramters;
+namespace Vectorface\OtpAuth\Parameters;
 
 enum Algorithm: string
 {
diff --git a/src/OtpAuth/Paramters/Type.php b/src/OtpAuth/Parameters/Type.php
similarity index 65%
rename from src/OtpAuth/Paramters/Type.php
rename to src/OtpAuth/Parameters/Type.php
index 176da02..ba7b5af 100644
--- a/src/OtpAuth/Paramters/Type.php
+++ b/src/OtpAuth/Parameters/Type.php
@@ -1,6 +1,6 @@
 <?php
 
-namespace Vectorface\OtpAuth\Paramters;
+namespace Vectorface\OtpAuth\Parameters;
 
 enum Type: string
 {
diff --git a/src/OtpAuth/UriBuilder.php b/src/OtpAuth/UriBuilder.php
index 7465bf9..7d94c2b 100644
--- a/src/OtpAuth/UriBuilder.php
+++ b/src/OtpAuth/UriBuilder.php
@@ -2,10 +2,12 @@
 
 namespace Vectorface\OtpAuth;
 
+use DomainException;
 use Endroid\QrCode\Builder\Builder;
 use Endroid\QrCode\Writer\PngWriter;
-use Vectorface\OtpAuth\Paramters\Algorithm;
-use Vectorface\OtpAuth\Paramters\Type;
+use InvalidArgumentException;
+use Vectorface\OtpAuth\Parameters\Algorithm;
+use Vectorface\OtpAuth\Parameters\Type;
 
 /**
  * A TOTP/HOTP URI builder
@@ -74,7 +76,7 @@ public function algorithm(Algorithm $algorithm): self
     public function digits(int $digits): self
     {
         if (!in_array($digits, self::DIGITS)) {
-            throw new \InvalidArgumentException("Number of digits must be 6 or 8");
+            throw new InvalidArgumentException("Number of digits must be 6 or 8");
         }
         $this->digits = $digits;
         return $this;
@@ -83,7 +85,7 @@ public function digits(int $digits): self
     public function counter(int $counter): self
     {
         if ($counter < 0) {
-            throw new \InvalidArgumentException("Counter must be an integer greater than or equal to zero");
+            throw new InvalidArgumentException("Counter must be an integer greater than or equal to zero");
         }
         $this->counter = $counter;
         return $this;
@@ -92,7 +94,7 @@ public function counter(int $counter): self
     public function period(int $period): self
     {
         if ($period < 1) {
-            throw new \InvalidArgumentException("Period must be an integer greater than zero");
+            throw new InvalidArgumentException("Period must be an integer greater than zero");
         }
         $this->period = $period;
         return $this;
@@ -101,19 +103,19 @@ public function period(int $period): self
     public function getUri(): string
     {
         if (!isset($this->secret)) {
-            throw new \DomainException("Secret is required for OTP URIs");
+            throw new DomainException("Secret is required for OTP URIs");
         }
 
         if ($this->type === Type::HOTP && !isset($this->counter)) {
-            throw new \DomainException("Counter is a required HOTP parameter");
+            throw new DomainException("Counter is a required HOTP parameter");
         }
 
         if ($this->type === Type::TOTP && isset($this->counter)) {
-            throw new \DomainException("Counter parameter does not apply to TOTP");
+            throw new DomainException("Counter parameter does not apply to TOTP");
         }
 
         if ($this->type === Type::HOTP && isset($this->period)) {
-            throw new \DomainException("Period parameter does not apply to HOTP");
+            throw new DomainException("Period parameter does not apply to HOTP");
         }
 
         $params = array_filter([
@@ -149,4 +151,4 @@ public function getQRCodeDataUri(): string
             ->build()
             ->getDataUri();
     }
-}
\ No newline at end of file
+}
diff --git a/tests/GoogleAuthenticatorTest.php b/tests/GoogleAuthenticatorTest.php
index 2a93516..d8f522f 100644
--- a/tests/GoogleAuthenticatorTest.php
+++ b/tests/GoogleAuthenticatorTest.php
@@ -5,7 +5,7 @@
 use Exception;
 use PHPUnit\Framework\TestCase;
 use Vectorface\GoogleAuthenticator;
-use Vectorface\OtpAuth\Paramters\Algorithm;
+use Vectorface\OtpAuth\Parameters\Algorithm;
 
 class GoogleAuthenticatorTest extends TestCase
 {
diff --git a/tests/OtpAuth/UriBuilderTest.php b/tests/OtpAuth/UriBuilderTest.php
index f6e79c8..2b6a2fa 100644
--- a/tests/OtpAuth/UriBuilderTest.php
+++ b/tests/OtpAuth/UriBuilderTest.php
@@ -3,9 +3,9 @@
 namespace Tests\Vectorface\OtpAuth;
 
 use PHPUnit\Framework\TestCase;
-use Vectorface\OtpAuth\Paramters\Type;
+use Vectorface\OtpAuth\Parameters\Type;
 use Vectorface\OtpAuth\UriBuilder;
-use Vectorface\OtpAuth\Paramters\Algorithm;
+use Vectorface\OtpAuth\Parameters\Algorithm;
 
 class UriBuilderTest extends TestCase
 {
@@ -113,4 +113,4 @@ public function invalidArgumentsProvider()
             "Period must be positive" => ["Period must be an integer greater than zero", 6, 0, 0],
         ];
     }
-}
\ No newline at end of file
+}