diff --git a/composer.json b/composer.json
index 499865c65c0d2d818deb90da2f11c9d6011a2beb..77a137ed698a5083772b8140fe270589b96667bb 100644
--- a/composer.json
+++ b/composer.json
@@ -21,7 +21,7 @@
     },
     "autoload-dev": {
         "psr-4": {
-            "SimpleSAML\\Test\\Module\\accounting\\": "tests/"
+            "SimpleSAML\\Test\\Module\\accounting\\": "tests/src"
         }
     },
     "require": {
diff --git a/src/Exceptions/ModuleConfiguration/InvalidConfigurationNameException.php b/src/Exceptions/ModuleConfiguration/InvalidConfigurationNameException.php
index 46e091d1e057ae4756eacd4400a6000ee3a809e1..51cb2435eb7b7a7b2798fba0fd18cffcbac2f33b 100644
--- a/src/Exceptions/ModuleConfiguration/InvalidConfigurationNameException.php
+++ b/src/Exceptions/ModuleConfiguration/InvalidConfigurationNameException.php
@@ -1,6 +1,6 @@
 <?php
 
-namespace SimpleSAML\Module\accounting\Exceptions;
+namespace SimpleSAML\Module\accounting\Exceptions\ModuleConfiguration;
 
 class InvalidConfigurationNameException extends \InvalidArgumentException
 {
diff --git a/src/ModuleConfiguration.php b/src/ModuleConfiguration.php
index 528ec940f2469a996e8b784eb4069dc6128a5289..4f22576400de13b5e32bed8c518726a5be9c3bb3 100644
--- a/src/ModuleConfiguration.php
+++ b/src/ModuleConfiguration.php
@@ -3,7 +3,7 @@
 namespace SimpleSAML\Module\accounting;
 
 use SimpleSAML\Configuration;
-use SimpleSAML\Module\accounting\Exceptions\InvalidConfigurationNameException;
+use SimpleSAML\Module\accounting\Exceptions\ModuleConfiguration\InvalidConfigurationNameException;
 
 class ModuleConfiguration
 {
diff --git a/tests/ModuleConfigurationTest.php b/tests/src/ModuleConfigurationTest.php
similarity index 83%
rename from tests/ModuleConfigurationTest.php
rename to tests/src/ModuleConfigurationTest.php
index 6184e79ae7bc4dd2b2bf2d4239801acb044d2a40..b9fa74563c4230929187a19b43de57102a3f1b0b 100644
--- a/tests/ModuleConfigurationTest.php
+++ b/tests/src/ModuleConfigurationTest.php
@@ -13,6 +13,7 @@ class ModuleConfigurationTest extends TestCase
 {
     public function testSample(): void
     {
+        // Configuration directory is set by phpunit using php ENV setting feature (check phpunit.xml).
         $moduleConfiguration = new ModuleConfiguration('module_accounting_basic.php');
 
         $this->assertInstanceOf(Configuration::class, $moduleConfiguration->getConfiguration());