diff --git a/config/phpstan/phpstan.neon b/config/phpstan/phpstan.neon
index 5a46ff53..816ab4bf 100644
--- a/config/phpstan/phpstan.neon
+++ b/config/phpstan/phpstan.neon
@@ -7,6 +7,9 @@ parameters:
 	ignoreErrors:
 		# Ignore errors caused by Template static class reflection
 		- '#Call to an undefined static method Template::[a-zA-Z0-9\\_]+\(\)\.#'
+
+		# Ignore errors caused by no type hints on class properties, as that's not available till PHP 7.4
+		- '#Property .+? has no typehint specified.#'
 	level:
 		7
 	paths:
diff --git a/lib/Core.php b/lib/Core.php
index 6ba2777c..117753e7 100644
--- a/lib/Core.php
+++ b/lib/Core.php
@@ -11,7 +11,7 @@ mb_http_output('UTF-8');
 date_default_timezone_set('UTC');
 
 // Custom error handler to output more details about the specific Apache request that caused an exception.
-set_exception_handler(function($ex){
+set_exception_handler(function(Throwable $ex): void{
 	$errorString = "----------------------------------------\n";
 	$errorString .= trim(vds(array_intersect_key($_SERVER, array('REQUEST_URI' => '', 'QUERY_STRING' => '', 'REQUEST_METHOD' => '', 'REDIRECT_QUERY_STRING' => '', 'REDIRECT_URL' => '', 'SCRIPT_FILENAME' => '', 'REMOTE_ADDR' => '', 'HTTP_COOKIE' => '', 'HTTP_USER_AGENT' => '', 'SCRIPT_URI' => ''))));
 
diff --git a/lib/CoreFunctions.php b/lib/CoreFunctions.php
index b1695e8a..c065ad43 100644
--- a/lib/CoreFunctions.php
+++ b/lib/CoreFunctions.php
@@ -5,21 +5,24 @@
 use function Safe\ob_end_clean;
 
 // Convenience alias of var_dump.
-function vd($var){
+function vd($var): void{
 	var_dump($var);
 }
 
 // var_dump($var) then die().
-function vdd($var){
+function vdd($var): void{
 	var_dump($var);
 	die();
 }
 
 // var_dump into a string.
-function vds($var){
+function vds($var): string{
 	ob_start();
 	var_dump($var);
 	$str = ob_get_contents();
+	if($str === false){
+		$str = '';
+	}
 	ob_end_clean();
 	return $str;
 }
diff --git a/lib/Ebook.php b/lib/Ebook.php
index 8947341c..0663d7d2 100644
--- a/lib/Ebook.php
+++ b/lib/Ebook.php
@@ -1,10 +1,11 @@
 <?
-use function Safe\preg_replace;
+use Safe\DateTime;
 use function Safe\file_get_contents;
-use function Safe\preg_match;
-use function Safe\glob;
-use function Safe\substr;
 use function Safe\json_encode;
+use function Safe\glob;
+use function Safe\preg_match;
+use function Safe\preg_replace;
+use function Safe\substr;
 
 class Ebook{
 	public $WwwFilesystemPath;
@@ -153,7 +154,10 @@ class Ebook{
 
 		$this->FullTitle = $this->NullIfEmpty($xml->xpath('/package/metadata/dc:title[@id="fulltitle"]'));
 
-		$this->Timestamp = new \DateTime((string)$xml->xpath('/package/metadata/dc:date')[0]);
+		$date = $xml->xpath('/package/metadata/dc:date');
+		if($date !== false && sizeof($date) > 0){
+			$this->Timestamp = new DateTime((string)$date[0]);
+		}
 
 		// Get SE tags
 		foreach($xml->xpath('/package/metadata/meta[@property="se:subject"]') ?: [] as $tag){
@@ -170,14 +174,22 @@ class Ebook{
 			$this->LocTags[] = (string)$tag;
 		}
 
-		// Figure out authors and contributors.
+		// Figure out authors and contributors
 		foreach($xml->xpath('/package/metadata/dc:creator') ?: [] as $author){
 			$id = '';
+
 			if($author->attributes() !== null){
 				$id = $author->attributes()->id;
 			}
+
+			$refines = null;
+			$refinesElement = $xml->xpath('/package/metadata/meta[@property="file-as"][@refines="#' . $id . '"]');
+			if($refinesElement !== false && sizeof($refinesElement) > 0){
+				$refines = (string)$refinesElement[0];
+			}
+
 			$this->Authors[] = new Contributor(	(string)$author,
-								(string)$xml->xpath('/package/metadata/meta[@property="file-as"][@refines="#' . $id . '"]')[0],
+								$refines,
 								$this->NullIfEmpty($xml->xpath('/package/metadata/meta[@property="se:name.person.full-name"][@refines="#' . $id . '"]')),
 								$this->NullIfEmpty($xml->xpath('/package/metadata/meta[@property="se:url.encyclopedia.wikipedia"][@refines="#' . $id . '"]'))
 							);
@@ -225,8 +237,20 @@ class Ebook{
 		$this->Description = $this->NullIfEmpty($xml->xpath('/package/metadata/dc:description'));
 		$this->Language = $this->NullIfEmpty($xml->xpath('/package/metadata/dc:language'));
 		$this->LongDescription = $this->NullIfEmpty($xml->xpath('/package/metadata/meta[@property="se:long-description"]'));
-		$this->WordCount = (int)$xml->xpath('/package/metadata/meta[@property="se:word-count"]')[0] ?? 0;
-		$this->ReadingEase = (float)$xml->xpath('/package/metadata/meta[@property="se:reading-ease.flesch"]')[0] ?? 0;
+
+		$wordCount = 0;
+		$wordCountElement = $xml->xpath('/package/metadata/meta[@property="se:word-count"]');
+		if($wordCountElement !== false && sizeof($wordCountElement) > 0){
+			$wordCount = (int)$wordCountElement[0];
+		}
+		$this->WordCount = $wordCount;
+
+		$readingEase = 0;
+		$readingEaseElement = $xml->xpath('/package/metadata/meta[@property="se:reading-ease.flesch"]');
+		if($readingEaseElement !== false && sizeof($readingEaseElement) > 0){
+			$readingEase = (float)$readingEaseElement[0];
+		}
+		$this->ReadingEase = $readingEase;
 
 		if($this->ReadingEase !== null){
 			if($this->ReadingEase >= 90){
@@ -479,9 +503,10 @@ class Ebook{
 		return $object;
 	}
 
+	/**
+	 * @param array<Contributor> $contributors
+	 */
 	private function GenerateContributorList(array $contributors): string{
-		// Inputs: An array of Contributor objects.
-
 		$string = '';
 		$i = 0;
 		foreach($contributors as $contributor){
diff --git a/lib/GitCommit.php b/lib/GitCommit.php
index a0dc9451..921abc92 100644
--- a/lib/GitCommit.php
+++ b/lib/GitCommit.php
@@ -1,10 +1,12 @@
 <?
+use Safe\DateTimeImmutable;
+
 class GitCommit{
 	public $Timestamp;
 	public $Message;
 
 	public function __construct(string $unixTimestamp, string $message){
-		$this->Timestamp = new \DateTimeImmutable('@' . $unixTimestamp);
+		$this->Timestamp = new DateTimeImmutable('@' . $unixTimestamp);
 		$this->Message = $message;
 	}
 }
diff --git a/lib/HttpInput.php b/lib/HttpInput.php
index f1c45a4a..68cb3b9d 100644
--- a/lib/HttpInput.php
+++ b/lib/HttpInput.php
@@ -1,6 +1,6 @@
 <?
 class HttpInput{
-	public static function GetString(string $variable, bool $allowEmptyString = true, $default = null): ?string{
+	public static function GetString(string $variable, bool $allowEmptyString = true, string $default = null): ?string{
 		$var = self::GetHttpVar($variable, HTTP_VAR_STR, GET, $default);
 
 		if(!$allowEmptyString && $var === ''){
@@ -10,15 +10,15 @@ class HttpInput{
 		return $var;
 	}
 
-	public static function GetInt(string $variable, $default = null): ?int{
+	public static function GetInt(string $variable, int $default = null): ?int{
 		return self::GetHttpVar($variable, HTTP_VAR_INT, GET, $default);
 	}
 
-	public static function GetBool(string $variable, $default = null): ?bool{
+	public static function GetBool(string $variable, bool $default = null): ?bool{
 		return self::GetHttpVar($variable, HTTP_VAR_BOOL, GET, $default);
 	}
 
-	public static function GetDec(string $variable, $default = null): ?float{
+	public static function GetDec(string $variable, float $default = null): ?float{
 		return self::GetHttpVar($variable, HTTP_VAR_DEC, GET, $default);
 	}
 
@@ -43,7 +43,6 @@ class HttpInput{
 			switch($type){
 				case HTTP_VAR_STR:
 					return $var;
-					break;
 				case HTTP_VAR_INT:
 					// Can't use ctype_digit because we may want negative integers
 					if(is_numeric($var) && mb_strpos($var, '.') === false){
@@ -62,7 +61,6 @@ class HttpInput{
 					else{
 						return true;
 					}
-					break;
 				case HTTP_VAR_DEC:
 					if(is_numeric($var)){
 						try{
diff --git a/lib/Library.php b/lib/Library.php
index 769e44b1..9a0ac837 100644
--- a/lib/Library.php
+++ b/lib/Library.php
@@ -6,6 +6,9 @@ use function Safe\unlink;
 use function Safe\usort;
 
 class Library{
+	/**
+	 * @return array<Ebook>
+	 */
 	public static function GetEbooks(string $sort = null): array{
 		$ebooks = [];
 
@@ -69,6 +72,9 @@ class Library{
 		return $ebooks;
 	}
 
+	/**
+	 * @return array<Ebook>
+	 */
 	public static function GetEbooksByAuthor(string $wwwFilesystemPath): array{
 		// Do we have the author's ebooks cached?
 		$ebooks = [];
@@ -82,6 +88,9 @@ class Library{
 		return $ebooks;
 	}
 
+	/**
+	 * @return array<Ebook>
+	 */
 	public static function GetEbooksByTag(string $tag): array{
 		// Do we have the tag's ebooks cached?
 		$ebooks = [];
@@ -95,6 +104,9 @@ class Library{
 		return $ebooks;
 	}
 
+	/**
+	 * @return array<Ebook>
+	 */
 	public static function GetEbooksByCollection(string $collection): array{
 		// Do we have the tag's ebooks cached?
 		$ebooks = [];
@@ -108,6 +120,9 @@ class Library{
 		return $ebooks;
 	}
 
+	/**
+	 * @return array<Ebook>
+	 */
 	public static function Search(string $query): array{
 		$ebooks = Library::GetEbooks();
 		$matches = [];
diff --git a/lib/Logger.php b/lib/Logger.php
index 15c55730..40f3269d 100644
--- a/lib/Logger.php
+++ b/lib/Logger.php
@@ -5,7 +5,7 @@ use function Safe\fclose;
 use function Safe\error_log;
 
 class Logger{
-	public static function WriteGithubWebhookLogEntry(string $requestId, string $text){
+	public static function WriteGithubWebhookLogEntry(string $requestId, string $text): void{
 		try{
 			$fp = fopen(GITHUB_WEBHOOK_LOG_FILE_PATH, 'a+');
 		}
@@ -18,7 +18,7 @@ class Logger{
 		fclose($fp);
 	}
 
-	public static function WriteErrorLogEntry(string $text){
+	public static function WriteErrorLogEntry(string $text): void{
 		error_log($text);
 	}
 }
diff --git a/lib/SeeOtherEbookException.php b/lib/SeeOtherEbookException.php
index def2120c..780431c4 100644
--- a/lib/SeeOtherEbookException.php
+++ b/lib/SeeOtherEbookException.php
@@ -2,7 +2,7 @@
 class SeeOtherEbookException extends \Exception{
 	public $Url;
 
-	public function __construct($url = ''){
+	public function __construct(string $url = ''){
 		$this->Url = $url;
 		parent::__construct('This ebook is at a different URL: ' . $url);
 	}
diff --git a/lib/WebhookException.php b/lib/WebhookException.php
index e76d62fd..48189862 100644
--- a/lib/WebhookException.php
+++ b/lib/WebhookException.php
@@ -2,7 +2,7 @@
 class WebhookException extends \Exception{
 	public $PostData;
 
-	public function __construct($message = '', $data = null){
+	public function __construct(string $message = '', string $data = null){
 		$this->PostData = $data;
 		parent::__construct($message);
 	}
diff --git a/www/webhooks/github.php b/www/webhooks/github.php
index de80bfa2..b66ddab8 100644
--- a/www/webhooks/github.php
+++ b/www/webhooks/github.php
@@ -41,7 +41,6 @@ try{
 			// Silence on success.
 			Logger::WriteGithubWebhookLogEntry($requestId, 'Event type: ping.');
 			throw new NoopException();
-			break;
 		case 'push':
 			Logger::WriteGithubWebhookLogEntry($requestId, 'Event type: push.');
 
@@ -114,7 +113,6 @@ try{
 			break;
 		default:
 			throw new WebhookException('Unrecognized GitHub webhook event.', $post);
-			break;
 	}
 
 	// "Success, no content"