diff --git a/modules/openapi-generator/src/main/resources/Java/libraries/webclient/ApiClient.mustache b/modules/openapi-generator/src/main/resources/Java/libraries/webclient/ApiClient.mustache
index 7f91fe44134..ed2dac7fa8c 100644
--- a/modules/openapi-generator/src/main/resources/Java/libraries/webclient/ApiClient.mustache
+++ b/modules/openapi-generator/src/main/resources/Java/libraries/webclient/ApiClient.mustache
@@ -2,6 +2,7 @@ package {{invokerPackage}};
 
 import com.fasterxml.jackson.databind.DeserializationFeature;
 import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.springframework.core.ParameterizedTypeReference;
@@ -88,16 +89,21 @@ public class ApiClient {
 
     public ApiClient() {
         this.dateFormat = createDefaultDateFormat();
-        this.webClient = buildWebClient(new ObjectMapper(), dateFormat);
+        ObjectMapper mapper = new ObjectMapper();
+        mapper.setDateFormat(dateFormat);
+        mapper.registerModule(new JavaTimeModule());
+        mapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
+
+        this.webClient = buildWebClient(mapper);
         this.init();
     }
 
     public ApiClient(ObjectMapper mapper, DateFormat format) {
-        this(buildWebClient(mapper.copy(), format), format);
+        this(buildWebClient(mapper.copy()), format);
     }
 
     public ApiClient(WebClient webClient, ObjectMapper mapper, DateFormat format) {
-        this(Optional.ofNullable(webClient).orElseGet(() ->buildWebClient(mapper.copy(), format)), format);
+        this(Optional.ofNullable(webClient).orElseGet(() ->buildWebClient(mapper.copy())), format);
     }
 
     private ApiClient(WebClient webClient, DateFormat format) {
@@ -126,9 +132,7 @@ public class ApiClient {
     * Build the RestTemplate used to make HTTP requests.
     * @return RestTemplate
     */
-    public static WebClient buildWebClient(ObjectMapper mapper, DateFormat dateFormat) {
-        mapper.setDateFormat(dateFormat);
-        mapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
+    public static WebClient buildWebClient(ObjectMapper mapper) {
         ExchangeStrategies strategies = ExchangeStrategies
             .builder()
             .codecs(clientDefaultCodecsConfigurer -> {
diff --git a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/ApiClient.java b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/ApiClient.java
index 7d5f7dd66bb..e8634916ba7 100644
--- a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/ApiClient.java
+++ b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/ApiClient.java
@@ -2,6 +2,7 @@ package org.openapitools.client;
 
 import com.fasterxml.jackson.databind.DeserializationFeature;
 import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.springframework.core.ParameterizedTypeReference;
@@ -88,16 +89,21 @@ public class ApiClient {
 
     public ApiClient() {
         this.dateFormat = createDefaultDateFormat();
-        this.webClient = buildWebClient(new ObjectMapper(), dateFormat);
+        ObjectMapper mapper = new ObjectMapper();
+        mapper.setDateFormat(dateFormat);
+        mapper.registerModule(new JavaTimeModule());
+        mapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
+
+        this.webClient = buildWebClient(mapper);
         this.init();
     }
 
     public ApiClient(ObjectMapper mapper, DateFormat format) {
-        this(buildWebClient(mapper.copy(), format), format);
+        this(buildWebClient(mapper.copy()), format);
     }
 
     public ApiClient(WebClient webClient, ObjectMapper mapper, DateFormat format) {
-        this(Optional.ofNullable(webClient).orElseGet(() ->buildWebClient(mapper.copy(), format)), format);
+        this(Optional.ofNullable(webClient).orElseGet(() ->buildWebClient(mapper.copy())), format);
     }
 
     private ApiClient(WebClient webClient, DateFormat format) {
@@ -127,9 +133,7 @@ public class ApiClient {
     * Build the RestTemplate used to make HTTP requests.
     * @return RestTemplate
     */
-    public static WebClient buildWebClient(ObjectMapper mapper, DateFormat dateFormat) {
-        mapper.setDateFormat(dateFormat);
-        mapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
+    public static WebClient buildWebClient(ObjectMapper mapper) {
         ExchangeStrategies strategies = ExchangeStrategies
             .builder()
             .codecs(clientDefaultCodecsConfigurer -> {