diff --git a/integration/admin-client/src/main/java/org/keycloak/admin/client/Keycloak.java b/integration/admin-client/src/main/java/org/keycloak/admin/client/Keycloak.java
index b3cf7adfa2..2b12225573 100755
--- a/integration/admin-client/src/main/java/org/keycloak/admin/client/Keycloak.java
+++ b/integration/admin-client/src/main/java/org/keycloak/admin/client/Keycloak.java
@@ -78,7 +78,7 @@ public class Keycloak {
                 .connectionPoolSize(10);
 
         if (customJacksonProvider != null) {
-            clientBuilder.register(customJacksonProvider);
+            clientBuilder.register(customJacksonProvider, 100);
         }
 
         return new Keycloak(serverUrl, realm, username, password, clientId, clientSecret, PASSWORD, clientBuilder.build(), null);
diff --git a/testsuite/integration-arquillian/tests/base/src/main/java/org/keycloak/testsuite/util/AdminClientUtil.java b/testsuite/integration-arquillian/tests/base/src/main/java/org/keycloak/testsuite/util/AdminClientUtil.java
index 316e0ec8cc..d18905a27a 100644
--- a/testsuite/integration-arquillian/tests/base/src/main/java/org/keycloak/testsuite/util/AdminClientUtil.java
+++ b/testsuite/integration-arquillian/tests/base/src/main/java/org/keycloak/testsuite/util/AdminClientUtil.java
@@ -64,7 +64,9 @@ public class AdminClientUtil {
         // We need to ignore unknown JSON properties e.g. in the adapter configuration representation
         // during adapter backward compatibility testing
         if (ignoreUnknownProperties) {
-            jacksonProvider = new ResteasyJackson2Provider();
+            // We need to use anonymous class to avoid the following error from RESTEasy:
+            // Provider class org.jboss.resteasy.plugins.providers.jackson.ResteasyJackson2Provider is already registered.  2nd registration is being ignored.
+            jacksonProvider = new ResteasyJackson2Provider() {};
             ObjectMapper objectMapper = new ObjectMapper();
             objectMapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
             jacksonProvider.setMapper(objectMapper);