diff --git a/builder/src/main/java/net/kemitix/checkstyle/ruleset/builder/RulesProperties.java b/builder/src/main/java/net/kemitix/checkstyle/ruleset/builder/RulesProperties.java
index b5adf8a..8818219 100644
--- a/builder/src/main/java/net/kemitix/checkstyle/ruleset/builder/RulesProperties.java
+++ b/builder/src/main/java/net/kemitix/checkstyle/ruleset/builder/RulesProperties.java
@@ -30,6 +30,7 @@ import lombok.extern.slf4j.Slf4j;
 import org.springframework.boot.context.properties.ConfigurationProperties;
 import org.springframework.context.annotation.Configuration;
 
+import java.util.ArrayList;
 import java.util.List;
 
 /**
@@ -47,5 +48,5 @@ class RulesProperties {
     /**
      * The Checkstyle checks.
      */
-    private List<Rule> rules;
+    private List<Rule> rules = new ArrayList<>();
 }