diff --git a/src/Errbit/Errbit.php b/src/Errbit/Errbit.php
index 954078c..88804b5 100644
--- a/src/Errbit/Errbit.php
+++ b/src/Errbit/Errbit.php
@@ -166,10 +166,14 @@ protected function shouldNotify(\Throwable $exception, array $skippedExceptions)
             }
         }
         $userAgent = $_SERVER['HTTP_USER_AGENT'] ?? '';
-        /** @var array<int, string> $ignoreUserAgents */
+        $userAgent = is_string($userAgent) ? $userAgent : '';
+        /** @var list<string> $ignoreUserAgents */
         $ignoreUserAgents = $this->config['ignore_user_agent'];
         foreach ($ignoreUserAgents as $ua) {
-            if ($userAgent !== '' && str_contains($userAgent, $ua)) {
+            if ($userAgent === '' || !is_string($ua) || $ua === '') {
+                continue;
+            }
+            if (str_contains($userAgent, $ua)) {
                 return false;
             }
         }
diff --git a/src/Errbit/Errors/BaseError.php b/src/Errbit/Errors/BaseError.php
index f120d5d..da91a5c 100644
--- a/src/Errbit/Errors/BaseError.php
+++ b/src/Errbit/Errors/BaseError.php
@@ -10,8 +10,12 @@
 abstract class BaseError extends \Exception
 {
     protected string $errorFile = '';
+    /** @var list<array<string, mixed>> */
     protected array $backtrace = [];
 
+    /**
+     * @param list<array<string, mixed>> $backtrace
+     */
     public function __construct(
         string $message = "",
         int $code = 0,
@@ -32,6 +36,9 @@ public function getErrorFile(): string
         return $this->errorFile;
     }
 
+    /**
+     * @return list<array<string, mixed>>
+     */
     public function getBacktrace(): array
     {
         return $this->backtrace;
diff --git a/src/Errbit/Errors/Error.php b/src/Errbit/Errors/Error.php
index ccc5087..8920efe 100644
--- a/src/Errbit/Errors/Error.php
+++ b/src/Errbit/Errors/Error.php
@@ -4,6 +4,9 @@
 
 class Error extends BaseError
 {
+    /**
+     * @param list<array<string, mixed>> $backtrace
+     */
     public function __construct(
         string $message,
         ?int $line = null,
diff --git a/src/Errbit/Errors/Notice.php b/src/Errbit/Errors/Notice.php
index cf31cff..9521f4c 100644
--- a/src/Errbit/Errors/Notice.php
+++ b/src/Errbit/Errors/Notice.php
@@ -4,6 +4,9 @@
 
 class Notice extends BaseError
 {
+    /**
+     * @param list<array<string, mixed>> $backtrace
+     */
     public function __construct(
         string $message,
         ?int $line = null,
diff --git a/src/Errbit/Errors/Warning.php b/src/Errbit/Errors/Warning.php
index 32e5da1..dc4b22b 100644
--- a/src/Errbit/Errors/Warning.php
+++ b/src/Errbit/Errors/Warning.php
@@ -4,6 +4,9 @@
 
 class Warning extends BaseError
 {
+    /**
+     * @param list<array<string, mixed>> $backtrace
+     */
     public function __construct(
         string $message,
         ?int $line = null,
diff --git a/src/Errbit/Utils/Converter.php b/src/Errbit/Utils/Converter.php
index 993ac9c..f3311b9 100644
--- a/src/Errbit/Utils/Converter.php
+++ b/src/Errbit/Utils/Converter.php
@@ -20,13 +20,16 @@ public static function createDefault(): Converter
         return new self();
     }
     
+    /**
+     * @param list<array<string, mixed>> $backtrace
+     */
     public function convert(int $code, string $message, ?\Throwable $previous = null, string $file ='', ?int $line = null, array $backtrace = []): \Throwable
     {
         return match ($code) {
             E_NOTICE, E_USER_NOTICE => new Notice($message, $line, $previous, $file, $backtrace),
             E_WARNING, E_USER_WARNING => new Warning($message, $line, $previous, $file, $backtrace),
-            E_RECOVERABLE_ERROR, E_ERROR, E_CORE_ERROR => new Fatal($message, $line, $previous,  $file),
-            default => new Error($message, $line, $previous,  $file, $backtrace),
+            E_RECOVERABLE_ERROR, E_ERROR, E_CORE_ERROR => new Fatal($message, $line ?? 0, $previous, $file),
+            default => new Error($message, $line, $previous, $file, $backtrace),
         };
     }
 }
diff --git a/src/Errbit/Utils/XmlBuilder.php b/src/Errbit/Utils/XmlBuilder.php
index c418ffc..a520fcf 100644
--- a/src/Errbit/Utils/XmlBuilder.php
+++ b/src/Errbit/Utils/XmlBuilder.php
@@ -31,7 +31,7 @@ class XmlBuilder
     /**
      * Instantiate a new XmlBuilder.
      *
-     * @param SimpleXMLElement $xml the parent node (only used internally)
+     * @param SimpleXMLElement|null $xml the parent node (only used internally)
      */
     public function __construct(?\SimpleXMLElement $xml = null)
     {
@@ -41,8 +41,8 @@ public function __construct(?\SimpleXMLElement $xml = null)
     /**
      * Insert a tag into the XML.
      *
-    * @param string $name the name of the tag, required.
-    * @param mixed $value the text value of the element, optional
+     * @param string $name the name of the tag, required.
+     * @param mixed $value the text value of the element, optional
      * @param array<string, mixed> $attributes an array of attributes for the tag, optional
      * @param callable|null $callback a callback to receive an XmlBuilder for the new tag, optional
      * @param bool $getLastChild whether to get the last child element
@@ -53,10 +53,16 @@ public function tag(string $name, mixed $value = '', array $attributes = [], ?ca
     {
         $idx = is_countable($this->_xml->$name) ? count($this->_xml->$name) : 0;
 
-        $this->_xml->{$name}[$idx] = $this->normalizeValue($value);
+        if (is_object($value)) {
+            $value = "[" . $value::class . "]";
+        } else {
+            $value = (string) $value;
+        }
+
+        $this->_xml->{$name}[$idx] = $value;
 
         foreach ($attributes as $attr => $v) {
-            $this->_xml->{$name}[$idx][$attr] = $this->normalizeValue($v);
+            $this->_xml->{$name}[$idx][(string) $attr] = (string) $v;
         }
         $node = new self($this->_xml->$name);
         if ($getLastChild) {
@@ -79,50 +85,18 @@ public function tag(string $name, mixed $value = '', array $attributes = [], ?ca
     /**
      * Add an attribute to the current element.
      *
-     * @param String $name  the name of the attribute
-     * @param String $value the value of the attribute
+     * @param string $name  the name of the attribute
+     * @param string $value the value of the attribute
      *
      * @return static the current builder
      */
-    public function attribute($name, $value): static
+    public function attribute(string $name, string $value): static
     {
-        $this->_xml[$name] = $this->normalizeValue($value);
+        $this->_xml[$name] = $value;
 
         return $this;
     }
 
-    /**
-     * Cast any scalar or object value into a string for XML nodes.
-     */
-    private function normalizeValue(mixed $value): string
-    {
-        if ($value instanceof \Stringable) {
-            return (string) $value;
-        }
-
-        if (is_object($value)) {
-            return sprintf('[%s]', $value::class);
-        }
-
-        if (is_bool($value)) {
-            return $value ? 'true' : 'false';
-        }
-
-        if (null === $value) {
-            return '';
-        }
-
-        if (is_resource($value)) {
-            return sprintf('[resource:%s]', get_resource_type($value));
-        }
-
-        if (is_array($value)) {
-            return '[array]';
-        }
-
-        return (string) $value;
-    }
-
     /**
      * Return this XmlBuilder as a string of XML.
      *
@@ -141,8 +115,10 @@ public function asXml(): string
      *
      * @return string escaped string
      */
-    public static function utf8ForXML($string)
+    public static function utf8ForXML(string $string): string
     {
-        return preg_replace('/[^\x{0009}\x{000a}\x{000d}\x{0020}-\x{D7FF}\x{E000}-\x{FFFD}]+/u', ' ', $string);
+        $filtered = preg_replace('/[^\x{0009}\x{000a}\x{000d}\x{0020}-\x{D7FF}\x{E000}-\x{FFFD}]+/u', ' ', $string);
+
+        return is_string($filtered) ? $filtered : '';
     }
 }