diff --git a/Classes/Backend/Preview.php b/Classes/Backend/Preview.php
index cf36e22..1006815 100644
--- a/Classes/Backend/Preview.php
+++ b/Classes/Backend/Preview.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace SkillDisplay\Typo3Extension\Backend;
 
 /*
diff --git a/Classes/Frontend/DataProcessing/SkillSets.php b/Classes/Frontend/DataProcessing/SkillSets.php
index 440b978..bfde225 100644
--- a/Classes/Frontend/DataProcessing/SkillSets.php
+++ b/Classes/Frontend/DataProcessing/SkillSets.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace SkillDisplay\Typo3Extension\Frontend\DataProcessing;
 
 /*
diff --git a/Classes/Frontend/DataProcessing/Skills.php b/Classes/Frontend/DataProcessing/Skills.php
index 6757bbc..77d3026 100644
--- a/Classes/Frontend/DataProcessing/Skills.php
+++ b/Classes/Frontend/DataProcessing/Skills.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace SkillDisplay\Typo3Extension\Frontend\DataProcessing;
 
 /*
diff --git a/Classes/SettingsFactory.php b/Classes/SettingsFactory.php
index a8821d4..2faebfa 100644
--- a/Classes/SettingsFactory.php
+++ b/Classes/SettingsFactory.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace SkillDisplay\Typo3Extension;
 
 /*
diff --git a/Classes/ViewHelpers/Verification/ButtonViewHelper.php b/Classes/ViewHelpers/Verification/ButtonViewHelper.php
index 0b644d8..86e0ece 100644
--- a/Classes/ViewHelpers/Verification/ButtonViewHelper.php
+++ b/Classes/ViewHelpers/Verification/ButtonViewHelper.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace SkillDisplay\Typo3Extension\ViewHelpers\Verification;
 
 /*
diff --git a/Classes/ViewHelpers/Verification/UrlViewHelper.php b/Classes/ViewHelpers/Verification/UrlViewHelper.php
index e87b36b..225989d 100644
--- a/Classes/ViewHelpers/Verification/UrlViewHelper.php
+++ b/Classes/ViewHelpers/Verification/UrlViewHelper.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace SkillDisplay\Typo3Extension\ViewHelpers\Verification;
 
 /*
diff --git a/Classes/ViewHelpers/VerificationViewHelper.php b/Classes/ViewHelpers/VerificationViewHelper.php
index 10309cb..d5d87ce 100644
--- a/Classes/ViewHelpers/VerificationViewHelper.php
+++ b/Classes/ViewHelpers/VerificationViewHelper.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace SkillDisplay\Typo3Extension\ViewHelpers;
 
 /*
diff --git a/Tests/Unit/Backend/PreviewTest.php b/Tests/Unit/Backend/PreviewTest.php
index f4b6d7e..766f6d1 100644
--- a/Tests/Unit/Backend/PreviewTest.php
+++ b/Tests/Unit/Backend/PreviewTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace SkillDisplay\Typo3Extension\Tests\Unit\Backend;
 
 /*
diff --git a/Tests/Unit/Frontend/DataProcessing/SkillSetsTest.php b/Tests/Unit/Frontend/DataProcessing/SkillSetsTest.php
index b3c4b92..2c5c796 100644
--- a/Tests/Unit/Frontend/DataProcessing/SkillSetsTest.php
+++ b/Tests/Unit/Frontend/DataProcessing/SkillSetsTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace SkillDisplay\Typo3Extension\Tests\Unit\Frontend\DataProcessing;
 
 /*
diff --git a/Tests/Unit/Frontend/DataProcessing/SkillsTest.php b/Tests/Unit/Frontend/DataProcessing/SkillsTest.php
index dcdc0b7..c4fd422 100644
--- a/Tests/Unit/Frontend/DataProcessing/SkillsTest.php
+++ b/Tests/Unit/Frontend/DataProcessing/SkillsTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace SkillDisplay\Typo3Extension\Tests\Unit\Frontend\DataProcessing;
 
 /*
diff --git a/Tests/Unit/SettingsFactoryTest.php b/Tests/Unit/SettingsFactoryTest.php
index 1422692..ecc6a84 100644
--- a/Tests/Unit/SettingsFactoryTest.php
+++ b/Tests/Unit/SettingsFactoryTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace SkillDisplay\Typo3Extension\Tests\Unit;
 
 /*
diff --git a/Tests/Unit/ViewHelpers/Verification/ButtonViewHelperTest.php b/Tests/Unit/ViewHelpers/Verification/ButtonViewHelperTest.php
index 1d3b49d..a5d8330 100644
--- a/Tests/Unit/ViewHelpers/Verification/ButtonViewHelperTest.php
+++ b/Tests/Unit/ViewHelpers/Verification/ButtonViewHelperTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace SkillDisplay\Typo3Extension\Tests\Unit\ViewHelpers\Verification;
 
 /*
diff --git a/Tests/Unit/ViewHelpers/Verification/UrlViewHelperTest.php b/Tests/Unit/ViewHelpers/Verification/UrlViewHelperTest.php
index a98ea0c..2ea4c86 100644
--- a/Tests/Unit/ViewHelpers/Verification/UrlViewHelperTest.php
+++ b/Tests/Unit/ViewHelpers/Verification/UrlViewHelperTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace SkillDisplay\Typo3Extension\Tests\Unit\ViewHelpers\Verification;
 
 /*
diff --git a/phpcs.xml.dist b/phpcs.xml.dist
index 131338c..57424f4 100644
--- a/phpcs.xml.dist
+++ b/phpcs.xml.dist
@@ -9,4 +9,8 @@
     <file>ext_localconf.php</file>
 
     <rule ref="PSR12" />
+    <rule ref="Generic.PHP.RequireStrictTypes">
+        <exclude-pattern>ext_*.php</exclude-pattern>
+        <exclude-pattern>Configuration/*</exclude-pattern>
+    </rule>
 </ruleset>