diff --git a/.github/CONTRIBUTING.md b/.github/CONTRIBUTING.md
index 5e1634a..f010c17 100644
--- a/.github/CONTRIBUTING.md
+++ b/.github/CONTRIBUTING.md
@@ -116,25 +116,25 @@ We will only merge pull requests that follow the project's coding style.
 Please check your code with the provided PHP_CodeSniffer standard:
 
 ```bash
-vendor/bin/phpcs --standard=vendor/phplist/phplist4-core/Configuration/PhpCodeSniffer/ Classes/ tests/
+vendor/bin/phpcs --standard=vendor/phplist/phplist4-core/Configuration/PhpCodeSniffer/ src/ tests/
 ```
 
 Please also check the code structure using PHPMD:
 
 ```bash
-vendor/bin/phpmd Classes/ text vendor/phplist/phplist4-core/Configuration/PHPMD/rules.xml
+vendor/bin/phpmd src/ text vendor/phplist/phplist4-core/Configuration/PHPMD/rules.xml
 ```
 
 And also please run the static code analysis:
 
 ```bash
-vendor/bin/phpstan analyse -l 5 Classes/ tests/
+vendor/bin/phpstan analyse -l 5 src/ tests/
 ```
 
 You can also run all code style checks using one long line from a bash shell:
 
 ```bash
-find Classes/ tests/ -name '*.php' -print0 | xargs -0 -n 1 -P 4 php -l && vendor/bin/phpstan analyse -l 5 Classes/ tests/ && vendor/bin/phpmd Classes/ text vendor/phplist/phplist4-core/Configuration/PHPMD/rules.xml && vendor/bin/phpcs --standard=vendor/phplist/phplist4-core/Configuration/PhpCodeSniffer/ Classes/ tests/
+find src/ tests/ -name '*.php' -print0 | xargs -0 -n 1 -P 4 php -l && vendor/bin/phpstan analyse -l 5 src/ tests/ && vendor/bin/phpmd src/ text vendor/phplist/phplist4-core/Configuration/PHPMD/rules.xml && vendor/bin/phpcs --standard=vendor/phplist/phplist4-core/Configuration/PhpCodeSniffer/ src/ tests/
 ```
 
 This will execute all tests except for the unit tests and the integration
diff --git a/.github/PULL_REQUEST_TEMPLATE.md b/.github/PULL_REQUEST_TEMPLATE.md
index 13650be..b4c9b3f 100644
--- a/.github/PULL_REQUEST_TEMPLATE.md
+++ b/.github/PULL_REQUEST_TEMPLATE.md
@@ -22,7 +22,7 @@ style?
 
 You can check for this using this command:
 
-    vendor/bin/phpcs --standard=PSR2 Classes/ tests/
+    vendor/bin/phpcs --standard=PSR2 src/ tests/
 
 
 ### Other Information
diff --git a/.travis.yml b/.travis.yml
index 5fbc25a..da04022 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -61,7 +61,7 @@ script:
 - >
   echo;
   echo "Linting all PHP files";
-  find Classes/ tests/ -name ''*.php'' -print0 | xargs -0 -n 1 -P 4 php -l;
+  find src/ tests/ -name ''*.php'' -print0 | xargs -0 -n 1 -P 4 php -l;
 
 - >
   echo;
@@ -76,14 +76,14 @@ script:
 - >
   echo;
   echo "Running the static analysis";
-  vendor/bin/phpstan analyse -l 5 Classes/ tests/;
+  vendor/bin/phpstan analyse -l 5 src/ tests/;
 
 - >
   echo;
   echo "Running PHPMD";
-  vendor/bin/phpmd Classes/ text vendor/phplist/phplist4-core/Configuration/PHPMD/rules.xml;
+  vendor/bin/phpmd src/ text vendor/phplist/phplist4-core/Configuration/PHPMD/rules.xml;
 
 - >
   echo;
   echo "Running PHP_CodeSniffer";
-  vendor/bin/phpcs --standard=vendor/phplist/phplist4-core/Configuration/PhpCodeSniffer/ Classes/ tests/;
+  vendor/bin/phpcs --standard=vendor/phplist/phplist4-core/Configuration/PhpCodeSniffer/ src/ tests/;
diff --git a/Configuration/services.yml b/Configuration/services.yml
index 6f7ca27..e95922e 100644
--- a/Configuration/services.yml
+++ b/Configuration/services.yml
@@ -1,6 +1,6 @@
 services:
     PhpList\RestBundle\Controller\:
-        resource: '../Classes/Controller'
+        resource: '../src/Controller'
         public: true
         autowire: true
         tags: ['controller.service_arguments']
diff --git a/composer.json b/composer.json
index ebd0970..7b1b997 100644
--- a/composer.json
+++ b/composer.json
@@ -44,7 +44,7 @@
     },
     "autoload": {
         "psr-4": {
-            "PhpList\\RestBundle\\": "Classes/"
+            "PhpList\\RestBundle\\": "src/"
         }
     },
     "autoload-dev": {
diff --git a/Classes/Controller/ListController.php b/src/Controller/ListController.php
similarity index 100%
rename from Classes/Controller/ListController.php
rename to src/Controller/ListController.php
diff --git a/Classes/Controller/SessionController.php b/src/Controller/SessionController.php
similarity index 100%
rename from Classes/Controller/SessionController.php
rename to src/Controller/SessionController.php
diff --git a/Classes/Controller/SubscriberController.php b/src/Controller/SubscriberController.php
similarity index 100%
rename from Classes/Controller/SubscriberController.php
rename to src/Controller/SubscriberController.php
diff --git a/Classes/Controller/Traits/AuthenticationTrait.php b/src/Controller/Traits/AuthenticationTrait.php
similarity index 100%
rename from Classes/Controller/Traits/AuthenticationTrait.php
rename to src/Controller/Traits/AuthenticationTrait.php
diff --git a/Classes/DependencyInjection/PhpListRestExtension.php b/src/DependencyInjection/PhpListRestExtension.php
similarity index 100%
rename from Classes/DependencyInjection/PhpListRestExtension.php
rename to src/DependencyInjection/PhpListRestExtension.php
diff --git a/Classes/PhpListRestBundle.php b/src/PhpListRestBundle.php
similarity index 100%
rename from Classes/PhpListRestBundle.php
rename to src/PhpListRestBundle.php