diff --git a/infection.json5 b/infection.json5
index 5b57c86d0..940e3a3c4 100644
--- a/infection.json5
+++ b/infection.json5
@@ -15,6 +15,6 @@
     "mutators": {
         "@default": true
     },
-    "timeout": 300,
+    "timeout": 30,
     "testFrameworkOptions": "--exclude-group=serial"
 }
diff --git a/src/Command/Api/ApiCommandHelper.php b/src/Command/Api/ApiCommandHelper.php
index feca40ffd..bb807ddbe 100644
--- a/src/Command/Api/ApiCommandHelper.php
+++ b/src/Command/Api/ApiCommandHelper.php
@@ -274,12 +274,14 @@ private function isApiSpecChecksumCacheValid(\Symfony\Component\Cache\CacheItem
   }
 
   /**
+   * Breaking caching during tests will cause performance issues and timeouts.
+   *
    * @return array<mixed>
+   * @infection-ignore-all
    */
   private function getCloudApiSpec(string $specFilePath): array {
     $cacheKey = basename($specFilePath);
     $cache = new PhpArrayAdapter(__DIR__ . '/../../../var/cache/' . $cacheKey . '.cache', new NullAdapter());
-    // @infection-ignore-all
     $cacheItemChecksum = $cache->getItem($cacheKey . '.checksum');
     $cacheItemSpec = $cache->getItem($cacheKey);
 
diff --git a/src/Helpers/LocalMachineHelper.php b/src/Helpers/LocalMachineHelper.php
index 84371adf4..9e9810a46 100644
--- a/src/Helpers/LocalMachineHelper.php
+++ b/src/Helpers/LocalMachineHelper.php
@@ -324,12 +324,15 @@ public function isBrowserAvailable(): bool {
   /**
    * Starts a background browser/tab for the current site or a specified URL.
    *
+   * Exclude from mutation testing as we don't want real browser windows opened.
+   *
    * @param string|null $uri Optional URI or site path to open in browser. If omitted, or if a site path
    *   is specified, the current site home page uri will be prepended if the site's
    *   hostname resolves.
    * @param string|null $browser The command to run to launch a browser.
    * @return bool TRUE if browser was opened. FALSE if browser was disabled by the user or a
    *   default browser could not be found.
+   * @infection-ignore-all
    */
   public function startBrowser(string $uri = NULL, string $browser = NULL): bool {
     // We can only open a browser if we have a DISPLAY environment variable on
diff --git a/tests/phpunit/src/Commands/Api/ApiCommandTest.php b/tests/phpunit/src/Commands/Api/ApiCommandTest.php
index 37162470d..4c93a3da3 100644
--- a/tests/phpunit/src/Commands/Api/ApiCommandTest.php
+++ b/tests/phpunit/src/Commands/Api/ApiCommandTest.php
@@ -361,12 +361,8 @@ public function providerTestApiCommandDefinitionParameters(): array {
 
   /**
    * @dataProvider providerTestApiCommandDefinitionParameters
-   * @param $useSpecCache
-   * @param $commandName
-   * @param $method
-   * @param $usage
    */
-  public function testApiCommandDefinitionParameters(mixed $useSpecCache, mixed $commandName, mixed $method, mixed $usage): void {
+  public function testApiCommandDefinitionParameters(string $useSpecCache, string $commandName, string $method, string $usage): void {
     putenv('ACQUIA_CLI_USE_CLOUD_API_SPEC_CACHE=' . $useSpecCache);
 
     $this->command = $this->getApiCommandByName($commandName);
diff --git a/tests/phpunit/src/Commands/DocsCommandTest.php b/tests/phpunit/src/Commands/DocsCommandTest.php
index b8e2f365f..cb7f3e1cc 100644
--- a/tests/phpunit/src/Commands/DocsCommandTest.php
+++ b/tests/phpunit/src/Commands/DocsCommandTest.php
@@ -21,7 +21,7 @@ protected function createCommand(): CommandBase {
   /**
    * @dataProvider providerTestDocsCommand
    */
-  public function testDocsCommand(mixed $input, mixed $expectedOutput): void {
+  public function testDocsCommand(int $input, string $expectedOutput): void {
     $localMachineHelper = $this->mockLocalMachineHelper();
     $localMachineHelper->startBrowser(Argument::any())->shouldBeCalled();