diff --git a/.travis.yml b/.travis.yml
index 569027d..46ca0bc 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -4,6 +4,7 @@ php:
   - '7.1'
   - '7.2'
   - '7.3'
+  - '7.4'
 
 before_script:
   - curl -L https://codeclimate.com/downloads/test-reporter/test-reporter-latest-linux-amd64 > ./cc-test-reporter
@@ -16,7 +17,7 @@ script:
   # Fail the Travis CI build on the first error.
   - set -e
   - mkdir -p build/logs
-  - php vendor/bin/phpcs --standard=PSR12 src
+  - php vendor/bin/phpcs --standard=PSR2 src
   - php vendor/bin/phpcs --standard=PSR1 tests
   - php vendor/bin/phpstan analyze --level max src
   - vendor/bin/phpunit --coverage-text --coverage-clover build/logs/clover.xml
diff --git a/composer.json b/composer.json
index e5b0df4..9800ce4 100644
--- a/composer.json
+++ b/composer.json
@@ -37,9 +37,6 @@
     "autoload-dev": {
         "psr-4": { "PHPExperts\\Combinatorics\\Tests\\" : "tests/" }
     },
-    "config": {
-        "classmap-authoritative": true
-    },
     "scripts": {
         "post-create-project-cmd": [
             "php install.php"
diff --git a/phpstan.neon b/phpstan.neon
new file mode 100644
index 0000000..22bf6eb
--- /dev/null
+++ b/phpstan.neon
@@ -0,0 +1,5 @@
+parameters:
+    checkMissingIterableValueType: false
+    paths:
+        - src/
+        - tests/
diff --git a/src/CombinationGenerator.php b/src/CombinationsGenerator.php
similarity index 100%
rename from src/CombinationGenerator.php
rename to src/CombinationsGenerator.php