diff --git a/config/checkstyle.properties b/config/checkstyle.properties
new file mode 100644
index 0000000..2db67e3
--- /dev/null
+++ b/config/checkstyle.properties
@@ -0,0 +1,8 @@
+
+checkstyle.suppressions.file=config/suppressions.xml
+checkstyle.suppressions-xpath.file=config/suppressions.xml
+checkstyle.header.file=https://raw.githubusercontent.com/checkstyle/checkstyle/master/config/java.header
+checkstyle.regexp.header.file=https://raw.githubusercontent.com/checkstyle/checkstyle/master/config/java-regexp.header
+checkstyle.importcontrol.file=config/import-control.xml
+checkstyle.importcontroltest.file=config/import-control-test.xml
+checkstyle.java.version=11
\ No newline at end of file
diff --git a/config/import-control-test.xml b/config/import-control-test.xml
new file mode 100644
index 0000000..76f669e
--- /dev/null
+++ b/config/import-control-test.xml
@@ -0,0 +1,10 @@
+<?xml version="1.0"?>
+<!DOCTYPE import-control PUBLIC
+        "-//Checkstyle//DTD ImportControl Configuration 1.3//EN"
+        "http://checkstyle.sourceforge.net/dtds/import_control_1_3.dtd">
+
+<import-control pkg="org.checkstyle.autofix">
+    <allow pkg="org.junit"/>
+    <allow pkg="org.openrewrite"/>
+    <allow pkg="org.checkstyle"/>
+</import-control>
\ No newline at end of file
diff --git a/config/import-control.xml b/config/import-control.xml
new file mode 100644
index 0000000..c2c794a
--- /dev/null
+++ b/config/import-control.xml
@@ -0,0 +1,13 @@
+<?xml version="1.0"?>
+<!DOCTYPE import-control PUBLIC
+        "-//Checkstyle//DTD ImportControl Configuration 1.2//EN"
+        "http://checkstyle.sourceforge.net/dtds/import_control_1_2.dtd">
+
+<import-control pkg="org.checkstyle.autofix" regex="true">
+    <allow pkg="org.openrewrite"/>
+    <allow pkg="org.openrewrite.java"/>
+    <allow pkg="org.openrewrite.java.tree"/>
+    <allow pkg="java"/>
+    <allow pkg="org.checkstyle"/>
+    <allow pkg="java.util"/>
+</import-control>
\ No newline at end of file
diff --git a/config/suppressions.xml b/config/suppressions.xml
new file mode 100644
index 0000000..1d3a562
--- /dev/null
+++ b/config/suppressions.xml
@@ -0,0 +1,13 @@
+<?xml version="1.0"?>
+
+<!DOCTYPE suppressions PUBLIC
+        "-//Checkstyle//DTD SuppressionFilter Configuration 1.1//EN"
+        "https://checkstyle.org/dtds/suppressions_1_1.dtd">
+
+<suppressions>
+    <suppress checks="HeaderCheck" files=".*"/>
+    <suppress checks="RegexpHeader" files=".*"/>
+    <suppress checks="header" files=".*\.java"/>
+    <suppress checks="multiFileRegexpHeader" files=".*"/>
+    <suppress checks="JavadocPackage" files=".*"/>
+</suppressions>
\ No newline at end of file
diff --git a/pom.xml b/pom.xml
index 13553e7..8e54ad6 100644
--- a/pom.xml
+++ b/pom.xml
@@ -24,6 +24,10 @@
         <recipe.bom.version>3.9.0</recipe.bom.version>
         <junit.version>5.13.0</junit.version>
         <assertj.version>3.24.2</assertj.version>
+
+        <!-- Checkstyle properties -->
+        <maven.checkstyle.plugin.version>3.6.0</maven.checkstyle.plugin.version>
+        <checkstyle.version>10.25.0</checkstyle.version>
     </properties>
 
     <dependencyManagement>
@@ -97,9 +101,46 @@
                     </systemPropertyVariables>
                 </configuration>
             </plugin>
+
+            <!-- Checkstyle plugin for code style regulation -->
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-checkstyle-plugin</artifactId>
+                <version>${maven.checkstyle.plugin.version}</version>
+                <dependencies>
+                    <dependency>
+                        <groupId>com.puppycrawl.tools</groupId>
+                        <artifactId>checkstyle</artifactId>
+                        <version>${checkstyle.version}</version>
+                    </dependency>
+                </dependencies>
+                <executions>
+                    <execution>
+                        <id>check</id>
+                        <goals>
+                            <goal>check</goal>
+                        </goals>
+                        <configuration>
+                            <includeResources>false</includeResources>
+                            <includeTestResources>false</includeTestResources>
+                            <includeTestSourceDirectory>true</includeTestSourceDirectory>
+                            <configLocation>
+                                https://raw.githubusercontent.com/checkstyle/checkstyle/checkstyle-${checkstyle.version}/config/checkstyle-checks.xml
+                            </configLocation>
+                            <propertiesLocation>config/checkstyle.properties</propertiesLocation>
+                            <failOnViolation>true</failOnViolation>
+                            <logViolationsToConsole>true</logViolationsToConsole>
+                            <maxAllowedViolations>0</maxAllowedViolations>
+                            <violationSeverity>error</violationSeverity>
+                            <outputFileFormat>xml</outputFileFormat>
+                            <outputFile>
+                                ${project.build.directory}/checkstyle/checkstyle-report.xml
+                            </outputFile>
+                        </configuration>
+                    </execution>
+                </executions>
+            </plugin>
         </plugins>
     </build>
 
-
-
 </project>
\ No newline at end of file
diff --git a/src/main/java/org/checkstyle/autofix/CheckstyleAutoFix.java b/src/main/java/org/checkstyle/autofix/CheckstyleAutoFix.java
index a46169a..6d13951 100644
--- a/src/main/java/org/checkstyle/autofix/CheckstyleAutoFix.java
+++ b/src/main/java/org/checkstyle/autofix/CheckstyleAutoFix.java
@@ -1,14 +1,13 @@
 package org.checkstyle.autofix;
 
-import org.openrewrite.Recipe;
-
 import java.util.Collections;
 import java.util.List;
 
 import org.checkstyle.autofix.recipe.UpperEllRecipe;
+import org.openrewrite.Recipe;
 
 /**
- * Main recipe that automatically fixes all supported Checkstyle violations
+ * Main recipe that automatically fixes all supported Checkstyle violations.
  */
 public class CheckstyleAutoFix extends Recipe {
 
@@ -26,7 +25,7 @@ public String getDescription() {
     public List<Recipe> getRecipeList() {
         return Collections.singletonList(
 
-            new UpperEllRecipe()
+                new UpperEllRecipe()
         );
     }
-}
\ No newline at end of file
+}
diff --git a/src/main/java/org/checkstyle/autofix/recipe/UpperEllRecipe.java b/src/main/java/org/checkstyle/autofix/recipe/UpperEllRecipe.java
index abfe4ec..a1ca5b9 100644
--- a/src/main/java/org/checkstyle/autofix/recipe/UpperEllRecipe.java
+++ b/src/main/java/org/checkstyle/autofix/recipe/UpperEllRecipe.java
@@ -20,7 +20,8 @@ public String getDisplayName() {
 
     @Override
     public String getDescription() {
-        return "Replace lowercase 'l' suffix in long literals with uppercase 'L' to improve readability.";
+        return "Replace lowercase 'l' suffix in long literals with uppercase 'L' "
+                + "to improve readability.";
     }
 
     @Override
@@ -28,17 +29,20 @@ public TreeVisitor<?, ExecutionContext> getVisitor() {
         return new UpperEllVisitor();
     }
 
-    private static class UpperEllVisitor extends JavaIsoVisitor<ExecutionContext> {
+    /**
+     * Visitor that replaces lowercase 'l' suffixes in long literals with uppercase 'L'.
+     */
+    private static final class UpperEllVisitor extends JavaIsoVisitor<ExecutionContext> {
         @Override
         public J.Literal visitLiteral(J.Literal literal, ExecutionContext ctx) {
             J.Literal result = super.visitLiteral(literal, ctx);
-            String valueSource = result.getValueSource();
+            final String valueSource = result.getValueSource();
 
             if (valueSource != null && valueSource.endsWith("l")
-                && result.getType() == JavaType.Primitive.Long) {
-                    String numericPart = valueSource.substring(0, valueSource.length() - 1);
-                    String newValueSource = numericPart + "L";
-                    result = result.withValueSource(newValueSource);
+                    && result.getType() == JavaType.Primitive.Long) {
+                final String numericPart = valueSource.substring(0, valueSource.length() - 1);
+                final String newValueSource = numericPart + "L";
+                result = result.withValueSource(newValueSource);
             }
             return result;
         }
diff --git a/src/test/java/org/checkstyle/autofix/recipe/UpperEllRecipeTest.java b/src/test/java/org/checkstyle/autofix/recipe/UpperEllRecipeTest.java
index a8c1cb5..fa047b0 100644
--- a/src/test/java/org/checkstyle/autofix/recipe/UpperEllRecipeTest.java
+++ b/src/test/java/org/checkstyle/autofix/recipe/UpperEllRecipeTest.java
@@ -1,12 +1,12 @@
 package org.checkstyle.autofix.recipe;
 
+import static org.junit.jupiter.api.Assertions.assertTrue;
+import static org.openrewrite.java.Assertions.java;
+
 import org.junit.jupiter.api.Test;
 import org.openrewrite.test.RecipeSpec;
 import org.openrewrite.test.RewriteTest;
 
-import static org.junit.jupiter.api.Assertions.assertTrue;
-import static org.openrewrite.java.Assertions.java;
-
 public class UpperEllRecipeTest implements RewriteTest {
 
     @Override
@@ -15,24 +15,24 @@ public void defaults(RecipeSpec spec) {
     }
 
     @Test
-    void fixesLowercaseLInLongLiteralsFromResources() {
+    void fixesLowercase() {
         rewriteRun(
 
             java(
-                "class Test {\n" +
-                "    int value1 = 123l;\n" +
-                "    long value2 = 0x123l;\n" +
-                "    long value3 = 0123l;\n" +
-                "    long value4 = 0b101l;\n" +
-                "    String value5 = null;\n" +
-                "}\n",
-                "class Test {\n" +
-                "    int value1 = 123L;\n" +
-                "    long value2 = 0x123L;\n" +
-                "    long value3 = 0123L;\n" +
-                "    long value4 = 0b101L;\n" +
-                "    String value5 = null;\n" +
-                "}\n"
+                "class Test {\n"
+                        + "    int value1 = 123l;\n"
+                        + "    long value2 = 0x123l;\n"
+                        + "    long value3 = 0123l;\n"
+                        + "    long value4 = 0b101l;\n"
+                        + "    String value5 = null;\n"
+                        + "}\n",
+                "class Test {\n"
+                        + "    int value1 = 123L;\n"
+                        + "    long value2 = 0x123L;\n"
+                        + "    long value3 = 0123L;\n"
+                        + "    long value4 = 0b101L;\n"
+                        + "    String value5 = null;\n"
+                        + "}\n"
             )
         );
         assertTrue(true, "Test completed successfully");