diff --git a/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/data/neo4j/Neo4jPropertiesTests.java b/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/data/neo4j/Neo4jPropertiesTests.java
index 2624a80d84..afbad5cce2 100644
--- a/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/data/neo4j/Neo4jPropertiesTests.java
+++ b/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/data/neo4j/Neo4jPropertiesTests.java
@@ -16,7 +16,8 @@
 
 package org.springframework.boot.autoconfigure.data.neo4j;
 
-import com.hazelcast.util.Base64;
+import java.util.Base64;
+
 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.Test;
 import org.neo4j.ogm.config.AutoIndexMode;
@@ -164,10 +165,8 @@ class Neo4jPropertiesTests {
 			assertThat(credentials).isNotNull();
 			Object content = credentials.credentials();
 			assertThat(content).isInstanceOf(String.class);
-			String[] auth = new String(Base64.decode(((String) content).getBytes())).split(":");
-			assertThat(auth[0]).isEqualTo(username);
-			assertThat(auth[1]).isEqualTo(password);
-			assertThat(auth).hasSize(2);
+			String[] auth = new String(Base64.getDecoder().decode((String) content)).split(":");
+			assertThat(auth).containsExactly(username, password);
 		}
 	}
 
diff --git a/src/checkstyle/checkstyle.xml b/src/checkstyle/checkstyle.xml
index bcdfea82a3..312d27601d 100644
--- a/src/checkstyle/checkstyle.xml
+++ b/src/checkstyle/checkstyle.xml
@@ -17,7 +17,7 @@
 			<property name="illegalPkgs"
 				value="^sun.*, ^org\.apache\.commons\.(?!compress|dbcp2|lang|lang3|logging|pool2).*, ^com\.google\.common.*, ^org\.flywaydb\.core\.internal.*, ^org\.testcontainers\.shaded.*" />
 			<property name="illegalClasses"
-				value="^reactor\.core\.support\.Assert, ^org\.junit\.rules\.ExpectedException, ^org\.slf4j\.LoggerFactory" />
+				value="^com\.hazelcast\.util\.Base64, ^org\.junit\.rules\.ExpectedException, ^org\.slf4j\.LoggerFactory, ^reactor\.core\.support\.Assert" />
 		</module>
 		<module
 			name="com.puppycrawl.tools.checkstyle.checks.imports.ImportControlCheck">