diff --git a/config/src/test/java/org/springframework/security/htmlunit/server/HtmlUnitWebTestClient.java b/config/src/test/java/org/springframework/security/htmlunit/server/HtmlUnitWebTestClient.java
index a24174c0ae..38af4387c7 100644
--- a/config/src/test/java/org/springframework/security/htmlunit/server/HtmlUnitWebTestClient.java
+++ b/config/src/test/java/org/springframework/security/htmlunit/server/HtmlUnitWebTestClient.java
@@ -27,7 +27,7 @@ import java.util.StringTokenizer;
 import org.htmlunit.FormEncodingType;
 import org.htmlunit.WebClient;
 import org.htmlunit.WebRequest;
-import org.htmlunit.util.Cookie;
+import org.htmlunit.http.Cookie;
 import org.htmlunit.util.NameValuePair;
 import reactor.core.publisher.Mono;
 
diff --git a/gradle/libs.versions.toml b/gradle/libs.versions.toml
index 4e02be55ea..a97fc43670 100644
--- a/gradle/libs.versions.toml
+++ b/gradle/libs.versions.toml
@@ -51,7 +51,7 @@ jakarta-websocket-jakarta-websocket-client-api = { module = "jakarta.websocket:j
 jakarta-xml-bind-jakarta-xml-bind-api = "jakarta.xml.bind:jakarta.xml.bind-api:4.0.5"
 ldapsdk = "ldapsdk:ldapsdk:4.1"
 net-sourceforge-htmlunit = "net.sourceforge.htmlunit:htmlunit:2.70.0"
-org-htmlunit-htmlunit = "org.htmlunit:htmlunit:4.21.0"
+org-htmlunit-htmlunit = "org.htmlunit:htmlunit:5.5.0"
 org-apache-httpcomponents-httpclient = "org.apache.httpcomponents.client5:httpclient5:5.6.4"
 org-apache-kerby-simplekdc='org.apache.kerby:kerb-simplekdc:2.1.2'
 org-apache-maven-maven-resolver-provider = "org.apache.maven:maven-resolver-provider:3.9.16"