diff --git a/.travis.yml b/.travis.yml
index 0cc13f91a..49822707f 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -25,7 +25,9 @@ matrix:
     - php: 7.1
     - php: 7.2
     - php: 7.3
-      env: PHPSTAN=1
+      env:
+        - deps=high
+        - PHPSTAN=1
     - php: 7.3
       env:
         - deps=high
@@ -64,8 +66,8 @@ script:
   - ls -d tests/Composer/Test/* | grep -v TestCase.php | parallel --gnu --keep-order 'echo "Running {} tests"; ./vendor/bin/phpunit -c tests/complete.phpunit.xml --colors=always {} || (echo -e "\e[41mFAILED\e[0m {}" && exit 1);'
   # Run PHPStan
   - if [[ $PHPSTAN == "1" ]]; then
-      bin/composer require --dev phpstan/phpstan-shim:^0.11 --ignore-platform-reqs &&
-      vendor/bin/phpstan.phar analyse --configuration=phpstan/config.neon;
+      bin/composer require --dev phpstan/phpstan:^0.12 &&
+      vendor/bin/phpstan analyse --configuration=phpstan/config.neon;
     fi
 
 before_deploy:
diff --git a/phpstan/config.neon b/phpstan/config.neon
index ae53ac531..09b42ed27 100644
--- a/phpstan/config.neon
+++ b/phpstan/config.neon
@@ -1,24 +1,12 @@
 parameters:
     autoload_files:
-        - phpstan/autoload.php
+        - autoload.php
     level: 0
     excludes_analyse:
-        - 'tests/Composer/Test/Fixtures'
-        - 'tests/Composer/Test/Autoload/Fixtures'
-        - 'tests/Composer/Test/Plugin/Fixtures'
+       - '../tests/Composer/Test/Fixtures/*'
+       - '../tests/Composer/Test/Autoload/Fixtures/*'
+       - '../tests/Composer/Test/Plugin/Fixtures/*'
     ignoreErrors:
-        # unused parameters
-        - '~^Constructor of class Composer\\Repository\\VcsRepository has an unused parameter \$dispatcher\.$~'
-        - '~^Constructor of class Composer\\Repository\\PearRepository has an unused parameter \$dispatcher\.$~'
-        - '~^Constructor of class Composer\\Util\\Http\\CurlDownloader has an unused parameter \$disableTls\.$~'
-        - '~^Constructor of class Composer\\Util\\Http\\CurlDownloader has an unused parameter \$options\.$~'
-        - '~^Constructor of class Composer\\Repository\\PearRepository has an unused parameter \$config\.$~'
-
-        # unused uses
-        - '~^Anonymous function has an unused use \$io\.$~'
-        - '~^Anonymous function has an unused use \$cache\.$~'
-        - '~^Anonymous function has an unused use \$path\.$~'
-
         # ion cube is not installed
         - '~^Function ioncube_loader_\w+ not found\.$~'
         # rar is not installed
@@ -33,14 +21,8 @@ parameters:
         # variable defined in eval
         - '~^Undefined variable: \$res$~'
 
-        # always checked whether the class exists
-        - '~^Instantiated class Symfony\\Component\\Console\\Terminal not found\.$~'
-        - '~^Class Symfony\\Component\\Console\\Input\\StreamableInputInterface not found\.$~'
-        - '~^Call to an undefined static method Symfony\\Component\\Process\\Process::fromShellCommandline\(\).$~'
-
-        # parent call in test mocks
-        - '~^Composer\\Test\\Mock\\HttpDownloaderMock::__construct\(\) does not call parent constructor from Composer\\Util\\HttpDownloader\.$~'
-        - '~^Composer\\Test\\Mock\\InstallationManagerMock::__construct\(\) does not call parent constructor from Composer\\Installer\\InstallationManager\.$~'
+        # we don't have different constructors for parent/child
+        - '~^Unsafe usage of new static\(\)\.$~'
     paths:
-        - src
-        - tests
+        - ../src
+        - ../tests
diff --git a/src/Composer/Downloader/FileDownloader.php b/src/Composer/Downloader/FileDownloader.php
index 7c7e45354..9775c27d9 100644
--- a/src/Composer/Downloader/FileDownloader.php
+++ b/src/Composer/Downloader/FileDownloader.php
@@ -113,7 +113,7 @@ class FileDownloader implements DownloaderInterface, ChangeReportInterface
 
         $accept = null;
         $reject = null;
-        $download = function () use ($io, $output, $httpDownloader, $cache, $eventDispatcher, $package, $fileName, $path, &$urls, &$accept, &$reject) {
+        $download = function () use ($io, $output, $httpDownloader, $cache, $eventDispatcher, $package, $fileName, &$urls, &$accept, &$reject) {
             $url = reset($urls);
 
             if ($eventDispatcher) {
@@ -160,7 +160,7 @@ class FileDownloader implements DownloaderInterface, ChangeReportInterface
             });
         };
 
-        $accept = function ($response) use ($io, $cache, $package, $fileName, $path, $self, &$urls) {
+        $accept = function ($response) use ($cache, $package, $fileName, $self, &$urls) {
             $url = reset($urls);
             $cacheKey = $url['cacheKey'];
 
@@ -174,7 +174,7 @@ class FileDownloader implements DownloaderInterface, ChangeReportInterface
             return $fileName;
         };
 
-        $reject = function ($e) use ($io, &$urls, $download, $fileName, $path, $package, &$retries, $filesystem, $self) {
+        $reject = function ($e) use ($io, &$urls, $download, $fileName, $package, &$retries, $filesystem, $self) {
             // clean up
             if (file_exists($fileName)) {
                 $filesystem->unlink($fileName);
diff --git a/src/Composer/Installer/InstallationManager.php b/src/Composer/Installer/InstallationManager.php
index 9c3fb6884..8d1579b63 100644
--- a/src/Composer/Installer/InstallationManager.php
+++ b/src/Composer/Installer/InstallationManager.php
@@ -246,7 +246,7 @@ class InstallationManager
                     $dispatcher->dispatchPackageEvent(constant($event), $devMode, $repo, $operations, $operation);
                 }
             }, function ($e) use ($jobType, $installer, $package, $initialPackage, $loop, $io) {
-                $this->io->writeError('    <error>' . ucfirst($jobType) .' of '.$package->getPrettyName().' failed</error>');
+                $io->writeError('    <error>' . ucfirst($jobType) .' of '.$package->getPrettyName().' failed</error>');
 
                 $promise = $installer->cleanup($jobType, $package, $initialPackage);
                 if ($promise) {
diff --git a/src/Composer/Repository/ComposerRepository.php b/src/Composer/Repository/ComposerRepository.php
index e4cfbba83..02f2a05fe 100644
--- a/src/Composer/Repository/ComposerRepository.php
+++ b/src/Composer/Repository/ComposerRepository.php
@@ -1119,7 +1119,7 @@ class ComposerRepository extends ArrayRepository implements ConfigurableReposito
             return $data;
         };
 
-        $reject = function ($e) use (&$retries, $httpDownloader, $filename, $options, &$reject, $accept, $io, $url, $cache, &$degradedMode) {
+        $reject = function ($e) use (&$retries, $httpDownloader, $filename, $options, &$reject, $accept, $io, $url, &$degradedMode) {
             if ($e instanceof TransportException && $e->getStatusCode() === 404) {
                 return false;
             }
diff --git a/src/Composer/Util/HttpDownloader.php b/src/Composer/Util/HttpDownloader.php
index c4b6c5424..8a117a232 100644
--- a/src/Composer/Util/HttpDownloader.php
+++ b/src/Composer/Util/HttpDownloader.php
@@ -190,7 +190,7 @@ class HttpDownloader
             $downloader->scheduleNextJob();
 
             return $response;
-        }, function ($e) use ($io, &$job, $downloader) {
+        }, function ($e) use (&$job, $downloader) {
             $job['status'] = HttpDownloader::STATUS_FAILED;
             $job['exception'] = $e;