diff --git a/spring-boot-modules/spring-boot-keycloak/src/main/java/com/baeldung/keycloak/SecurityConfig.java b/spring-boot-modules/spring-boot-keycloak/src/main/java/com/baeldung/keycloak/SecurityConfig.java
index eb7767480f..5b9ce9677a 100644
--- a/spring-boot-modules/spring-boot-keycloak/src/main/java/com/baeldung/keycloak/SecurityConfig.java
+++ b/spring-boot-modules/spring-boot-keycloak/src/main/java/com/baeldung/keycloak/SecurityConfig.java
@@ -4,6 +4,7 @@ import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.core.annotation.Order;
 import org.springframework.security.authentication.AuthenticationManager;
+import org.springframework.security.config.Customizer;
 import org.springframework.security.config.annotation.authentication.builders.AuthenticationManagerBuilder;
 import org.springframework.security.config.annotation.web.builders.HttpSecurity;
 import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity;
@@ -53,7 +54,8 @@ class SecurityConfig {
             .hasRole("USER")
             .anyRequest()
             .authenticated();
-        http.oauth2ResourceServer(OAuth2ResourceServerConfigurer::jwt);
+        http.oauth2ResourceServer((oauth2) -> oauth2
+            .jwt(Customizer.withDefaults()));
         return http.build();
     }
 
diff --git a/spring-boot-modules/spring-boot-keycloak/src/main/java/com/baeldung/keycloaksoap/KeycloakSecurityConfig.java b/spring-boot-modules/spring-boot-keycloak/src/main/java/com/baeldung/keycloaksoap/KeycloakSecurityConfig.java
index e55d307e33..70b306eaee 100644
--- a/spring-boot-modules/spring-boot-keycloak/src/main/java/com/baeldung/keycloaksoap/KeycloakSecurityConfig.java
+++ b/spring-boot-modules/spring-boot-keycloak/src/main/java/com/baeldung/keycloaksoap/KeycloakSecurityConfig.java
@@ -3,6 +3,7 @@ package com.baeldung.keycloaksoap;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
+import org.springframework.security.config.Customizer;
 import org.springframework.security.config.annotation.method.configuration.EnableGlobalMethodSecurity;
 import org.springframework.security.config.annotation.web.builders.HttpSecurity;
 import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity;
@@ -21,7 +22,8 @@ public class KeycloakSecurityConfig {
             .disable()
             .authorizeHttpRequests(auth -> auth.anyRequest()
                 .authenticated())
-            .oauth2ResourceServer(OAuth2ResourceServerConfigurer::jwt);
+            .oauth2ResourceServer((oauth2) -> oauth2
+                .jwt(Customizer.withDefaults()));
         return http.build();
     }
 }