diff --git a/MO4/ruleset.xml b/MO4/ruleset.xml
index ec99418..acd4451 100644
--- a/MO4/ruleset.xml
+++ b/MO4/ruleset.xml
@@ -103,6 +103,8 @@
     <rule ref="SlevomatCodingStandard.Classes.ModernClassNameReference"/>
     <!-- report invalid format of inline phpDocs with @var -->
     <rule ref="SlevomatCodingStandard.Commenting.InlineDocCommentDeclaration"/>
+    <!-- TODO -->
+    <rule ref="SlevomatCodingStandard.Commenting.UselessFunctionDocComment"/>
     <!-- Forbid useless @inheritDoc comments -->
     <rule ref="SlevomatCodingStandard.Commenting.UselessInheritDocComment"/>
     <!-- Forbid assignments in conditions -->
@@ -129,6 +131,10 @@
     <rule ref="SlevomatCodingStandard.ControlStructures.NewWithParentheses"/>
     <!-- Require usage of null coalesce operator when possible -->
     <rule ref="SlevomatCodingStandard.ControlStructures.RequireNullCoalesceOperator"/>
+    <!-- Require usage of null coalesce equal operator when possible -->
+    <rule ref="SlevomatCodingStandard.ControlStructures.RequireNullCoalesceEqualOperator"/>
+    <!-- Require usage of null safe operator when possible -->
+    <rule ref="SlevomatCodingStandard.ControlStructures.RequireNullSafeObjectOperator"/>
     <!-- Require usage of ternary operator when possible -->
     <rule ref="SlevomatCodingStandard.ControlStructures.RequireTernaryOperator">
         <!-- But multiline is useful for readability -->
@@ -207,7 +213,7 @@
         <severity>0</severity>
     </rule>
     <rule ref="SlevomatCodingStandard.TypeHints.ParameterTypeHint.MissingTraversableTypeHintSpecification">
-        <severity>0</severity>
+        <severity>9</severity>
     </rule>
     <!-- Require return type hints to be declared -->
     <rule ref="SlevomatCodingStandard.TypeHints.ReturnTypeHint">
@@ -217,8 +223,9 @@
         </properties>
     </rule>
     <rule ref="SlevomatCodingStandard.TypeHints.ReturnTypeHint.UselessAnnotation">
-        <severity>0</severity>
+        <severity>9</severity>
     </rule>
+    <!-- TODO -->
     <rule ref="SlevomatCodingStandard.TypeHints.ReturnTypeHint.MissingTraversableTypeHintSpecification">
         <severity>0</severity>
     </rule>
diff --git a/composer.json b/composer.json
index 7b2336e..268e07b 100644
--- a/composer.json
+++ b/composer.json
@@ -22,7 +22,7 @@
         "source": "https://github.com/mayflower/mo4-coding-standard"
     },
     "require": {
-        "php": "~7.2 || ~8.0",
+        "php": "~7.4 || ~8.0",
         "dealerdirect/phpcodesniffer-composer-installer": "~0.7",
         "escapestudios/symfony2-coding-standard": "^3.10.0",
         "slevomat/coding-standard": "^7.0.1",