diff --git a/klab.authentication/src/main/java/org/integratedmodelling/klab/communication/client/Client.java b/klab.authentication/src/main/java/org/integratedmodelling/klab/communication/client/Client.java
index 0cee21733..0b7e64430 100644
--- a/klab.authentication/src/main/java/org/integratedmodelling/klab/communication/client/Client.java
+++ b/klab.authentication/src/main/java/org/integratedmodelling/klab/communication/client/Client.java
@@ -25,6 +25,7 @@
 import java.io.IOException;
 import java.lang.reflect.Array;
 import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -107,7 +108,7 @@ public class Client extends RestTemplate implements IClient {
 
     ObjectMapper objectMapper;
     String authToken;
-    MediaType contentType = MediaType.APPLICATION_JSON;
+    MediaType contentType = new MediaType(MediaType.APPLICATION_JSON, StandardCharsets.UTF_8);
     RestTemplate basicTemplate;
     private Set<String> endpoints = new HashSet<>();