diff --git a/config/src/test/resources/serialized/6.4.x/org.springframework.security.ldap.userdetails.LdapUserDetailsManager$PasswordModifyRequest.serialized b/config/src/test/resources/serialized/6.4.x/org.springframework.security.ldap.userdetails.LdapUserDetailsManager$PasswordModifyRequest.serialized
new file mode 100644
index 0000000000..39ce303aa0
Binary files /dev/null and b/config/src/test/resources/serialized/6.4.x/org.springframework.security.ldap.userdetails.LdapUserDetailsManager$PasswordModifyRequest.serialized differ
diff --git a/config/src/test/resources/serialized/6.4.x/org.springframework.security.oauth2.server.resource.introspection.SpringOpaqueTokenIntrospector$ArrayListFromString.serialized b/config/src/test/resources/serialized/6.4.x/org.springframework.security.oauth2.server.resource.introspection.SpringOpaqueTokenIntrospector$ArrayListFromString.serialized
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/config/src/test/resources/serialized/6.4.x/org.springframework.security.oauth2.server.resource.introspection.SpringReactiveOpaqueTokenIntrospector$ArrayListFromString.serialized b/config/src/test/resources/serialized/6.4.x/org.springframework.security.oauth2.server.resource.introspection.SpringReactiveOpaqueTokenIntrospector$ArrayListFromString.serialized
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/ldap/src/main/java/org/springframework/security/ldap/userdetails/LdapUserDetailsManager.java b/ldap/src/main/java/org/springframework/security/ldap/userdetails/LdapUserDetailsManager.java
index 43f136403a..53d46980ac 100644
--- a/ldap/src/main/java/org/springframework/security/ldap/userdetails/LdapUserDetailsManager.java
+++ b/ldap/src/main/java/org/springframework/security/ldap/userdetails/LdapUserDetailsManager.java
@@ -18,6 +18,7 @@
 
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
+import java.io.Serial;
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.LinkedList;
@@ -491,6 +492,9 @@ private void changePasswordUsingExtensionOperation(LdapName userDn, String oldPa
 	 */
 	private static class PasswordModifyRequest implements ExtendedRequest {
 
+		@Serial
+		private static final long serialVersionUID = 3154223576081503237L;
+
 		private static final byte SEQUENCE_TYPE = 48;
 
 		private static final String PASSWORD_MODIFY_OID = "1.3.6.1.4.1.4203.1.11.1";
diff --git a/oauth2/oauth2-resource-server/src/main/java/org/springframework/security/oauth2/server/resource/introspection/SpringOpaqueTokenIntrospector.java b/oauth2/oauth2-resource-server/src/main/java/org/springframework/security/oauth2/server/resource/introspection/SpringOpaqueTokenIntrospector.java
index 18723e6743..4674ab7886 100644
--- a/oauth2/oauth2-resource-server/src/main/java/org/springframework/security/oauth2/server/resource/introspection/SpringOpaqueTokenIntrospector.java
+++ b/oauth2/oauth2-resource-server/src/main/java/org/springframework/security/oauth2/server/resource/introspection/SpringOpaqueTokenIntrospector.java
@@ -16,6 +16,7 @@
 
 package org.springframework.security.oauth2.server.resource.introspection;
 
+import java.io.Serial;
 import java.net.URI;
 import java.time.Instant;
 import java.util.ArrayList;
@@ -271,6 +272,9 @@ private Collection<GrantedAuthority> authorities(List<String> scopes) {
 	// gh-7563
 	private static final class ArrayListFromString extends ArrayList<String> {
 
+		@Serial
+		private static final long serialVersionUID = -1804103555781637109L;
+
 		ArrayListFromString(String... elements) {
 			super(Arrays.asList(elements));
 		}
diff --git a/oauth2/oauth2-resource-server/src/main/java/org/springframework/security/oauth2/server/resource/introspection/SpringReactiveOpaqueTokenIntrospector.java b/oauth2/oauth2-resource-server/src/main/java/org/springframework/security/oauth2/server/resource/introspection/SpringReactiveOpaqueTokenIntrospector.java
index ae342cb169..7c6bf8ecb0 100644
--- a/oauth2/oauth2-resource-server/src/main/java/org/springframework/security/oauth2/server/resource/introspection/SpringReactiveOpaqueTokenIntrospector.java
+++ b/oauth2/oauth2-resource-server/src/main/java/org/springframework/security/oauth2/server/resource/introspection/SpringReactiveOpaqueTokenIntrospector.java
@@ -16,6 +16,7 @@
 
 package org.springframework.security.oauth2.server.resource.introspection;
 
+import java.io.Serial;
 import java.net.URI;
 import java.time.Instant;
 import java.util.ArrayList;
@@ -225,6 +226,9 @@ private Collection<GrantedAuthority> authorities(List<String> scopes) {
 	// gh-7563
 	private static final class ArrayListFromString extends ArrayList<String> {
 
+		@Serial
+		private static final long serialVersionUID = 9182779930765511117L;
+
 		ArrayListFromString(String... elements) {
 			super(Arrays.asList(elements));
 		}