diff --git a/pom.xml b/pom.xml
index 45f73cb8..35ae77ca 100644
--- a/pom.xml
+++ b/pom.xml
@@ -213,7 +213,7 @@
             <plugin>
                 <groupId>net.revelc.code.formatter</groupId>
                 <artifactId>formatter-maven-plugin</artifactId>
-                <version>2.18.0</version>
+                <version>2.23.0</version>
                 <configuration>
                     <configFile>${project.basedir}/src/etc/eclipse-code-formatter.xml</configFile>
                     <encoding>UTF-8</encoding>
diff --git a/src/main/java/am/ik/yavi/core/ConstraintViolations.java b/src/main/java/am/ik/yavi/core/ConstraintViolations.java
index 0f0f1904..c53e5e3d 100644
--- a/src/main/java/am/ik/yavi/core/ConstraintViolations.java
+++ b/src/main/java/am/ik/yavi/core/ConstraintViolations.java
@@ -492,7 +492,7 @@ public final int size() {
 	 *
 	 * <pre>
 	 * {@code
-	 *      list.subList(from, to).clear();
+	 * list.subList(from, to).clear();
 	 * }
 	 * </pre>
 	 *
diff --git a/src/test/java/am/ik/yavi/fn/ValidationTest.java b/src/test/java/am/ik/yavi/fn/ValidationTest.java
index d3f4908a..e5110363 100644
--- a/src/test/java/am/ik/yavi/fn/ValidationTest.java
+++ b/src/test/java/am/ik/yavi/fn/ValidationTest.java
@@ -202,8 +202,8 @@ void orElseThrowFailure() {
 		assertThatThrownBy(() -> Validation
 				.<String, String> failure(Arrays.asList("e1", "e2"))
 				.orElseThrow(errors -> new IllegalArgumentException("errors=" + errors)))
-						.hasMessage("errors=[e1, e2]")
-						.isInstanceOf(IllegalArgumentException.class);
+				.hasMessage("errors=[e1, e2]")
+				.isInstanceOf(IllegalArgumentException.class);
 	}
 
 	@Test
@@ -219,4 +219,4 @@ void orElseGetFailure() {
 				.orElseGet(errors -> String.join(",", errors));
 		assertThat(s).isEqualTo("e1,e2");
 	}
-}
\ No newline at end of file
+}