diff --git a/lib/private/Archive/TAR.php b/lib/private/Archive/TAR.php
index 9dc906384e0fb..a6140e44eb629 100644
--- a/lib/private/Archive/TAR.php
+++ b/lib/private/Archive/TAR.php
@@ -197,7 +197,7 @@ public function getFolder(string $path): array {
 				if ($pos = strpos($result, '/')) {
 					$result = substr($result, 0, $pos + 1);
 				}
-				if (array_search($result, $folderContent) === false) {
+				if (!in_array($result, $folderContent)) {
 					$folderContent[] = $result;
 				}
 			}
@@ -269,7 +269,7 @@ public function extract(string $dest): bool {
 	 */
 	public function fileExists(string $path): bool {
 		$files = $this->getFiles();
-		if ((array_search($path, $files) !== false) or (array_search($path . '/', $files) !== false)) {
+		if ((in_array($path, $files)) or (in_array($path . '/', $files))) {
 			return true;
 		} else {
 			$folderPath = rtrim($path, '/') . '/';
diff --git a/lib/private/Command/AsyncBus.php b/lib/private/Command/AsyncBus.php
index ec6fbc91f68a2..c65e6cad78e56 100644
--- a/lib/private/Command/AsyncBus.php
+++ b/lib/private/Command/AsyncBus.php
@@ -82,7 +82,7 @@ private function runCommand($command) {
 	private function canRunAsync($command) {
 		$traits = $this->getTraits($command);
 		foreach ($traits as $trait) {
-			if (array_search($trait, $this->syncTraits) !== false) {
+			if (in_array($trait, $this->syncTraits)) {
 				return false;
 			}
 		}
diff --git a/lib/private/Files/Cache/Cache.php b/lib/private/Files/Cache/Cache.php
index 27db4dfe8099a..46228af565b15 100644
--- a/lib/private/Files/Cache/Cache.php
+++ b/lib/private/Files/Cache/Cache.php
@@ -454,7 +454,7 @@ protected function normalizeData(array $data): array {
 		$params = [];
 		$extensionParams = [];
 		foreach ($data as $name => $value) {
-			if (array_search($name, $fields) !== false) {
+			if (in_array($name, $fields)) {
 				if ($name === 'path') {
 					$params['path_hash'] = md5($value);
 				} elseif ($name === 'mimetype') {
@@ -474,7 +474,7 @@ protected function normalizeData(array $data): array {
 				}
 				$params[$name] = $value;
 			}
-			if (array_search($name, $extensionFields) !== false) {
+			if (in_array($name, $extensionFields)) {
 				$extensionParams[$name] = $value;
 			}
 		}
diff --git a/lib/private/Files/Cache/Watcher.php b/lib/private/Files/Cache/Watcher.php
index acc76f263dc57..61ea5b2f848d4 100644
--- a/lib/private/Files/Cache/Watcher.php
+++ b/lib/private/Files/Cache/Watcher.php
@@ -129,7 +129,7 @@ public function update($path, $cachedData) {
 	 * @return bool
 	 */
 	public function needsUpdate($path, $cachedData) {
-		if ($this->watchPolicy === self::CHECK_ALWAYS or ($this->watchPolicy === self::CHECK_ONCE and array_search($path, $this->checkedPaths) === false)) {
+		if ($this->watchPolicy === self::CHECK_ALWAYS or ($this->watchPolicy === self::CHECK_ONCE and !in_array($path, $this->checkedPaths))) {
 			$this->checkedPaths[] = $path;
 			return $this->storage->hasUpdated($path, $cachedData['storage_mtime']);
 		}
diff --git a/lib/private/Group/Manager.php b/lib/private/Group/Manager.php
index 47475121ea0cf..da99187f130e9 100644
--- a/lib/private/Group/Manager.php
+++ b/lib/private/Group/Manager.php
@@ -371,7 +371,7 @@ public function isAdmin($userId) {
 	 * @return bool if in group
 	 */
 	public function isInGroup($userId, $group) {
-		return array_search($group, $this->getUserIdGroupIds($userId)) !== false;
+		return in_array($group, $this->getUserIdGroupIds($userId));
 	}
 
 	/**
diff --git a/lib/private/Hooks/EmitterTrait.php b/lib/private/Hooks/EmitterTrait.php
index da4e3da2bd659..fe9cba893de31 100644
--- a/lib/private/Hooks/EmitterTrait.php
+++ b/lib/private/Hooks/EmitterTrait.php
@@ -43,7 +43,7 @@ public function listen($scope, $method, callable $callback) {
 		if (!isset($this->listeners[$eventName])) {
 			$this->listeners[$eventName] = [];
 		}
-		if (array_search($callback, $this->listeners[$eventName], true) === false) {
+		if (!in_array($callback, $this->listeners[$eventName], true)) {
 			$this->listeners[$eventName][] = $callback;
 		}
 	}
diff --git a/lib/private/legacy/OC_App.php b/lib/private/legacy/OC_App.php
index 23e0b099e9112..579c38b2d7c98 100644
--- a/lib/private/legacy/OC_App.php
+++ b/lib/private/legacy/OC_App.php
@@ -564,7 +564,7 @@ public function listAllApps(): array {
 		$supportedApps = $this->getSupportedApps();
 
 		foreach ($installedApps as $app) {
-			if (array_search($app, $blacklist) === false) {
+			if (!in_array($app, $blacklist)) {
 				$info = $appManager->getAppInfo($app, false, $langCode);
 				if (!is_array($info)) {
 					\OCP\Server::get(LoggerInterface::class)->error('Could not read app info file for app "' . $app . '"', ['app' => 'core']);
diff --git a/lib/private/legacy/OC_User.php b/lib/private/legacy/OC_User.php
index 5751b813f2cc5..d2dc2a2389f7c 100644
--- a/lib/private/legacy/OC_User.php
+++ b/lib/private/legacy/OC_User.php
@@ -138,7 +138,7 @@ public static function setupBackends() {
 			$class = $config['class'];
 			$arguments = $config['arguments'];
 			if (class_exists($class)) {
-				if (array_search($i, self::$_setupedBackends) === false) {
+				if (!in_array($i, self::$_setupedBackends)) {
 					// make a reflection object
 					$reflectionObj = new ReflectionClass($class);