diff --git a/.phpstan.neon b/.phpstan.neon
index fb731728b8..15d3ec15fb 100644
--- a/.phpstan.neon
+++ b/.phpstan.neon
@@ -2,6 +2,9 @@
 #
 # SPDX-License-Identifier: CC0-1.0
 
+includes:
+    - vendor/phpstan/phpstan-strict-rules/rules.neon
+
 parameters:
     level: 3
 
@@ -23,6 +26,10 @@ parameters:
     dynamicConstantNames:
         - DB_UPDATE_VERSION
 
+    # See all rules at https://github.com/phpstan/phpstan-strict-rules/blob/2.0.x/rules.neon
+    strictRules:
+        allRules: false
+
     ignoreErrors:
         -
             # Ignore missing GdImage class in PHP <= 7.4
diff --git a/composer.json b/composer.json
index 9973336590..fc26674ca7 100644
--- a/composer.json
+++ b/composer.json
@@ -157,6 +157,7 @@
 		"php-mock/php-mock-phpunit": "^2.10",
 		"phpmd/phpmd": "^2.15",
 		"phpstan/phpstan": "^2.0",
+		"phpstan/phpstan-strict-rules": "^2.0",
 		"phpunit/phpunit": "^9"
 	},
 	"scripts": {
diff --git a/composer.lock b/composer.lock
index fb9fadddbd..ab66a33d05 100644
--- a/composer.lock
+++ b/composer.lock
@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "897b878d6db24b9a6437bd9f971478be",
+    "content-hash": "e93a8ac7e31cf3e5e0ca76134e5ffa0b",
     "packages": [
         {
             "name": "asika/simple-console",
@@ -5849,6 +5849,54 @@
             ],
             "time": "2024-11-11T15:43:04+00:00"
         },
+        {
+            "name": "phpstan/phpstan-strict-rules",
+            "version": "2.0.0",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/phpstan/phpstan-strict-rules.git",
+                "reference": "a4a6a08bd4a461e516b9c3b8fdbf0f1883b34158"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/phpstan/phpstan-strict-rules/zipball/a4a6a08bd4a461e516b9c3b8fdbf0f1883b34158",
+                "reference": "a4a6a08bd4a461e516b9c3b8fdbf0f1883b34158",
+                "shasum": ""
+            },
+            "require": {
+                "php": "^7.4 || ^8.0",
+                "phpstan/phpstan": "^2.0"
+            },
+            "require-dev": {
+                "php-parallel-lint/php-parallel-lint": "^1.2",
+                "phpstan/phpstan-deprecation-rules": "^2.0",
+                "phpstan/phpstan-phpunit": "^2.0",
+                "phpunit/phpunit": "^9.6"
+            },
+            "type": "phpstan-extension",
+            "extra": {
+                "phpstan": {
+                    "includes": [
+                        "rules.neon"
+                    ]
+                }
+            },
+            "autoload": {
+                "psr-4": {
+                    "PHPStan\\": "src/"
+                }
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "MIT"
+            ],
+            "description": "Extra strict and opinionated rules for PHPStan",
+            "support": {
+                "issues": "https://github.com/phpstan/phpstan-strict-rules/issues",
+                "source": "https://github.com/phpstan/phpstan-strict-rules/tree/2.0.0"
+            },
+            "time": "2024-10-26T16:04:33+00:00"
+        },
         {
             "name": "phpunit/php-code-coverage",
             "version": "9.2.31",
diff --git a/src/Console/Worker.php b/src/Console/Worker.php
index 97b7160d03..09ff5f6599 100644
--- a/src/Console/Worker.php
+++ b/src/Console/Worker.php
@@ -92,5 +92,7 @@ HELP;
 		CoreWorker::unclaimProcess($process);
 
 		$this->processRepo->delete($process);
+
+		return;
 	}
 }
diff --git a/src/Content/Pager.php b/src/Content/Pager.php
index 0cdf5c0e4a..222247c6f5 100644
--- a/src/Content/Pager.php
+++ b/src/Content/Pager.php
@@ -208,15 +208,15 @@ class Pager
 				'class' => $this->getPage() == 1 ? 'disabled' : ''
 			];
 
-			$numpages = $totalItemCount / $this->getItemsPerPage();
+			$numpages = (int) ceil($totalItemCount / $this->getItemsPerPage());
 
 			$numstart = 1;
 			$numstop = $numpages;
 
 			// Limit the number of displayed page number buttons.
 			if ($numpages > 8) {
-				$numstart = (($this->getPage() > 4) ? ($this->getPage() - 4) : 1);
-				$numstop = (($this->getPage() > ($numpages - 7)) ? $numpages : ($numstart + 8));
+				$numstart = ($this->getPage() > 4) ? ($this->getPage() - 4) : 1;
+				$numstop = ($this->getPage() > ($numpages - 7)) ? $numpages : ($numstart + 8);
 			}
 
 			$pages = [];
@@ -237,22 +237,6 @@ class Pager
 				}
 			}
 
-			if (($totalItemCount % $this->getItemsPerPage()) != 0) {
-				if ($i == $this->getPage()) {
-					$pages[$i] = [
-						'url'   => '#',
-						'text'  => $i,
-						'class' => 'current active'
-					];
-				} else {
-					$pages[$i] = [
-						'url'   => Strings::ensureQueryParameter($this->baseQueryString . '&page=' . $i),
-						'text'  => $i,
-						'class' => 'n'
-					];
-				}
-			}
-
 			$data['pages'] = $pages;
 
 			$lastpage = (($numpages > intval($numpages)) ? intval($numpages)+1 : $numpages);
diff --git a/src/Content/Text/HTML.php b/src/Content/Text/HTML.php
index 72c61f38cc..701125dd27 100644
--- a/src/Content/Text/HTML.php
+++ b/src/Content/Text/HTML.php
@@ -55,7 +55,7 @@ class HTML
 
 		$xpath = new DOMXPath($doc);
 
-		/** @var \DOMNode[] $list */
+		/** @var \DOMNodeList<\DOMNode>|false $list */
 		$list = $xpath->query("//" . $tag);
 		foreach ($list as $node) {
 			$attr = [];
@@ -1018,7 +1018,7 @@ class HTML
 	 */
 	public static function checkRelMeLink(DOMDocument $doc, UriInterface $meUrl): bool
 	{
-		$xpath = new \DOMXpath($doc);
+		$xpath = new \DOMXPath($doc);
 
 		// This expression checks that "me" is among the space-delimited values of the "rel" attribute.
 		// And that the href attribute contains exactly the provided URL
diff --git a/src/Core/Lock/Type/AbstractLock.php b/src/Core/Lock/Type/AbstractLock.php
index 9d8b5849b2..6854be267c 100644
--- a/src/Core/Lock/Type/AbstractLock.php
+++ b/src/Core/Lock/Type/AbstractLock.php
@@ -28,7 +28,7 @@ abstract class AbstractLock implements ICanLock
 	 */
 	protected function hasAcquiredLock(string $key): bool
 	{
-		return isset($this->acquireLock[$key]) && $this->acquiredLocks[$key] === true;
+		return isset($this->acquiredLocks[$key]) && $this->acquiredLocks[$key] === true;
 	}
 
 	/**
diff --git a/src/Core/Session/Handler/Cache.php b/src/Core/Session/Handler/Cache.php
index 7629d9a164..65b87872a7 100644
--- a/src/Core/Session/Handler/Cache.php
+++ b/src/Core/Session/Handler/Cache.php
@@ -99,8 +99,11 @@ class Cache extends AbstractSessionHandler
 	}
 
 	#[\ReturnTypeWillChange]
-	public function gc($max_lifetime): bool
+	/**
+	 * @return int|false
+	 */
+	public function gc($max_lifetime)
 	{
-		return true;
+		return 0; // Cache does not support garbage collection, so we return 0 to indicate no action taken
 	}
 }
diff --git a/src/Core/Session/Handler/Database.php b/src/Core/Session/Handler/Database.php
index 3ef64294b9..d8146139a1 100644
--- a/src/Core/Session/Handler/Database.php
+++ b/src/Core/Session/Handler/Database.php
@@ -124,13 +124,23 @@ class Database extends AbstractSessionHandler
 	}
 
 	#[\ReturnTypeWillChange]
-	public function gc($max_lifetime): bool
+	/**
+	 * @return int|false
+	 */
+	public function gc($max_lifetime)
 	{
 		try {
-			return $this->dba->delete('session', ["`expire` < ?", time()]);
+			$result = $this->dba->delete('session', ["`expire` < ?", time()]);
 		} catch (\Exception $exception) {
 			$this->logger->warning('Cannot use garbage collector.', ['exception' => $exception]);
 			return false;
 		}
+
+		if ($result !== false) {
+			// TODO: DBA::delete() returns true, but we need to return the number of deleted rows as interger
+			$result = 0;
+		}
+
+		return $result;
 	}
 }
diff --git a/src/Core/Worker.php b/src/Core/Worker.php
index fd33278502..fd2ab5c242 100644
--- a/src/Core/Worker.php
+++ b/src/Core/Worker.php
@@ -521,7 +521,7 @@ class Worker
 		}
 
 		if ($sleeping) {
-			DI::logger()->info('Cooldown ended.', ['max-load' => $load_cooldown, 'max-processes' => $processes_cooldown, 'load' => $load, 'called-by' => System::callstack(1)]);
+			DI::logger()->info('Cooldown ended.', ['max-load' => $load_cooldown, 'max-processes' => $processes_cooldown, 'load' => $load ?? [], 'called-by' => System::callstack(1)]);
 		}
 	}
 
diff --git a/src/Database/PostUpdate.php b/src/Database/PostUpdate.php
index 6aebda8096..031c2fec1d 100644
--- a/src/Database/PostUpdate.php
+++ b/src/Database/PostUpdate.php
@@ -193,7 +193,7 @@ class PostUpdate
 			Contact::removeDuplicates($contact['nurl'], $contact['uid']);
 		}
 
-		DBA::close($contact);
+		DBA::close($contacts);
 		DI::keyValue()->set('post_update_version', 1322);
 
 		DI::logger()->info('Done');
diff --git a/src/Network/Probe.php b/src/Network/Probe.php
index 471f6e313a..92ee97b816 100644
--- a/src/Network/Probe.php
+++ b/src/Network/Probe.php
@@ -8,7 +8,7 @@
 namespace Friendica\Network;
 
 use DOMDocument;
-use DomXPath;
+use DOMXPath;
 use Exception;
 use Friendica\Content\Text\HTML;
 use Friendica\Core\Hook;
@@ -1273,7 +1273,7 @@ class Probe
 			return [];
 		}
 
-		$xpath = new DomXPath($doc);
+		$xpath = new DOMXPath($doc);
 
 		$vcards = $xpath->query("//div[contains(concat(' ', @class, ' '), ' vcard ')]");
 		if (!is_object($vcards)) {
diff --git a/src/Object/Image.php b/src/Object/Image.php
index 0aad761341..283a8d4895 100644
--- a/src/Object/Image.php
+++ b/src/Object/Image.php
@@ -363,12 +363,11 @@ class Image
 	 * Rotates image
 	 *
 	 * @param integer $degrees degrees to rotate image
-	 * @return mixed
 	 */
-	public function rotate(int $degrees)
+	public function rotate(int $degrees): void
 	{
 		if (!$this->isValid()) {
-			return false;
+			return;
 		}
 
 		if ($this->isImagick()) {
@@ -393,12 +392,11 @@ class Image
 	 *
 	 * @param boolean $horiz optional, default true
 	 * @param boolean $vert  optional, default false
-	 * @return mixed
 	 */
-	public function flip(bool $horiz = true, bool $vert = false)
+	public function flip(bool $horiz = true, bool $vert = false): void
 	{
 		if (!$this->isValid()) {
-			return false;
+			return;
 		}
 
 		if ($this->isImagick()) {
diff --git a/src/Util/HTTPSignature.php b/src/Util/HTTPSignature.php
index a779a59a86..c5a182f98e 100644
--- a/src/Util/HTTPSignature.php
+++ b/src/Util/HTTPSignature.php
@@ -592,7 +592,7 @@ class HTTPSignature
 			return [];
 		}
 
-		$sig_block = self::parseSigHeader($http_headers['HTTP_SIGNATURE']);
+		$sig_block = self::parseSigheader($http_headers['HTTP_SIGNATURE']);
 
 		if (empty($sig_block['keyId'])) {
 			DI::logger()->debug('No keyId', ['sig_block' => $sig_block]);
@@ -652,7 +652,7 @@ class HTTPSignature
 			}
 		}
 
-		$sig_block = self::parseSigHeader($http_headers['HTTP_SIGNATURE']);
+		$sig_block = self::parseSigheader($http_headers['HTTP_SIGNATURE']);
 
 		// Add fields from the signature block to the header. See issue 8845
 		if (!empty($sig_block['created']) && empty($headers['(created)'])) {