diff --git a/samples/client/petstore/java/resttemplate-withXml/src/main/java/io/swagger/client/ApiClient.java b/samples/client/petstore/java/resttemplate-withXml/src/main/java/io/swagger/client/ApiClient.java
index cf28fc5a47d..e16a241aaf9 100644
--- a/samples/client/petstore/java/resttemplate-withXml/src/main/java/io/swagger/client/ApiClient.java
+++ b/samples/client/petstore/java/resttemplate-withXml/src/main/java/io/swagger/client/ApiClient.java
@@ -263,6 +263,9 @@ public class ApiClient {
      * @return ApiClient this client
      */
     public ApiClient addDefaultHeader(String name, String value) {
+        if (defaultHeaders.containsKey(name)) {
+            defaultHeaders.remove(name);
+        }
         defaultHeaders.add(name, value);
         return this;
     }
diff --git a/samples/client/petstore/java/resttemplate/src/main/java/io/swagger/client/ApiClient.java b/samples/client/petstore/java/resttemplate/src/main/java/io/swagger/client/ApiClient.java
index 75b19b6d9fa..b905f6a27c4 100644
--- a/samples/client/petstore/java/resttemplate/src/main/java/io/swagger/client/ApiClient.java
+++ b/samples/client/petstore/java/resttemplate/src/main/java/io/swagger/client/ApiClient.java
@@ -258,6 +258,9 @@ public class ApiClient {
      * @return ApiClient this client
      */
     public ApiClient addDefaultHeader(String name, String value) {
+        if (defaultHeaders.containsKey(name)) {
+            defaultHeaders.remove(name);
+        }
         defaultHeaders.add(name, value);
         return this;
     }