diff --git a/client/src/main/java/ctbrec/ui/sites/fc2live/Fc2UpdateService.java b/client/src/main/java/ctbrec/ui/sites/fc2live/Fc2UpdateService.java
index 4c3631b2..0de1728b 100644
--- a/client/src/main/java/ctbrec/ui/sites/fc2live/Fc2UpdateService.java
+++ b/client/src/main/java/ctbrec/ui/sites/fc2live/Fc2UpdateService.java
@@ -41,7 +41,7 @@ public class Fc2UpdateService extends PaginatedScheduledService {
         return new Task<List<Model>>() {
             @Override
             public List<Model> call() throws IOException {
-                RequestBody body = RequestBody.create(null, new byte[0]);
+                RequestBody body = RequestBody.create(new byte[0]);
                 Request req = new Request.Builder()
                         .url(url)
                         .method("POST", body)
diff --git a/common/src/main/java/ctbrec/recorder/RemoteRecorder.java b/common/src/main/java/ctbrec/recorder/RemoteRecorder.java
index 7ecb4cf2..a7b7ea0a 100644
--- a/common/src/main/java/ctbrec/recorder/RemoteRecorder.java
+++ b/common/src/main/java/ctbrec/recorder/RemoteRecorder.java
@@ -103,7 +103,7 @@ public class RemoteRecorder implements Recorder {
     private Optional<String> sendRequest(String action) throws IOException, InvalidKeyException, NoSuchAlgorithmException {
         String msg = "{\"action\": \"" + action + "\"}";
         LOG.debug("Sending request to recording server: {}", msg);
-        RequestBody requestBody = RequestBody.create(JSON, msg);
+        RequestBody requestBody = RequestBody.Companion.create(msg, JSON);
         Request.Builder builder = new Request.Builder().url(getRecordingEndpoint()).post(requestBody);
         addHmacIfNeeded(msg, builder);
         Request request = builder.build();
@@ -121,7 +121,7 @@ public class RemoteRecorder implements Recorder {
     private void sendRequest(String action, Model model) throws IOException, InvalidKeyException, NoSuchAlgorithmException {
         String payload = modelRequestAdapter.toJson(new ModelRequest(action, model));
         LOG.debug("Sending request to recording server: {}", payload);
-        RequestBody body = RequestBody.create(JSON, payload);
+        RequestBody body = RequestBody.Companion.create(payload, JSON);
         Request.Builder builder = new Request.Builder().url(getRecordingEndpoint()).post(body);
         addHmacIfNeeded(payload, builder);
         Request request = builder.build();
@@ -148,7 +148,7 @@ public class RemoteRecorder implements Recorder {
     private void sendRequest(String action, Recording recording, Runnable... onSuccess) throws InvalidKeyException, NoSuchAlgorithmException, IOException {
         RecordingRequest recReq = new RecordingRequest(action, recording);
         String msg = recordingRequestAdapter.toJson(recReq);
-        RequestBody body = RequestBody.create(JSON, msg);
+        RequestBody body = RequestBody.Companion.create(msg, JSON);
         Request.Builder builder = new Request.Builder().url(getRecordingEndpoint()).post(body);
         addHmacIfNeeded(msg, builder);
         Request request = builder.build();
@@ -233,7 +233,7 @@ public class RemoteRecorder implements Recorder {
         private void syncSpace() {
             try {
                 String msg = "{\"action\": \"space\"}";
-                RequestBody body = RequestBody.create(JSON, msg);
+                RequestBody body = RequestBody.Companion.create(msg, JSON);
                 Request.Builder builder = new Request.Builder().url(getRecordingEndpoint()).post(body);
                 addHmacIfNeeded(msg, builder);
                 Request request = builder.build();
@@ -268,7 +268,7 @@ public class RemoteRecorder implements Recorder {
         private void syncModels() {
             try {
                 String msg = "{\"action\": \"list\"}";
-                RequestBody body = RequestBody.create(JSON, msg);
+                RequestBody body = RequestBody.Companion.create(msg, JSON);
                 Request.Builder builder = new Request.Builder().url(getRecordingEndpoint()).post(body);
                 addHmacIfNeeded(msg, builder);
                 Request request = builder.build();
@@ -301,7 +301,7 @@ public class RemoteRecorder implements Recorder {
         private void syncOnlineModels() {
             try {
                 String msg = "{\"action\": \"listOnline\"}";
-                RequestBody body = RequestBody.create(JSON, msg);
+                RequestBody body = RequestBody.Companion.create(msg, JSON);
                 Request.Builder builder = new Request.Builder().url(getRecordingEndpoint()).post(body);
                 addHmacIfNeeded(msg, builder);
                 Request request = builder.build();
@@ -333,7 +333,7 @@ public class RemoteRecorder implements Recorder {
         private void syncRecordings() {
             try {
                 String msg = "{\"action\": \"recordings\"}";
-                RequestBody body = RequestBody.create(JSON, msg);
+                RequestBody body = RequestBody.Companion.create(msg, JSON);
                 Request.Builder builder = new Request.Builder().url(getRecordingEndpoint()).post(body);
                 addHmacIfNeeded(msg, builder);
                 Request request = builder.build();
@@ -555,7 +555,7 @@ public class RemoteRecorder implements Recorder {
         RecordingRequest recReq = new RecordingRequest("rerunPostProcessing", recording);
         String msg = recordingRequestAdapter.toJson(recReq);
         LOG.debug(msg);
-        RequestBody body = RequestBody.create(JSON, msg);
+        RequestBody body = RequestBody.Companion.create(msg, JSON);
         Request.Builder builder = new Request.Builder().url(getRecordingEndpoint()).post(body);
         addHmacIfNeeded(msg, builder);
         Request request = builder.build();
diff --git a/common/src/main/java/ctbrec/sites/camsoda/CamsodaModel.java b/common/src/main/java/ctbrec/sites/camsoda/CamsodaModel.java
index 6266f8e1..22ff4191 100644
--- a/common/src/main/java/ctbrec/sites/camsoda/CamsodaModel.java
+++ b/common/src/main/java/ctbrec/sites/camsoda/CamsodaModel.java
@@ -291,7 +291,7 @@ public class CamsodaModel extends AbstractModel {
         String csrfToken = ((CamsodaHttpClient)site.getHttpClient()).getCsrfToken();
         Request request = new Request.Builder()
                 .url(url)
-                .post(RequestBody.create(null, ""))
+                .post(RequestBody.create(new byte[0]))
                 .addHeader(REFERER, Camsoda.BASE_URI + '/' + getName())
                 .addHeader(USER_AGENT, Config.getInstance().getSettings().httpUserAgent)
                 .addHeader(ACCEPT, MIMETYPE_APPLICATION_JSON)
@@ -314,7 +314,7 @@ public class CamsodaModel extends AbstractModel {
         String csrfToken = ((CamsodaHttpClient)site.getHttpClient()).getCsrfToken();
         Request request = new Request.Builder()
                 .url(url)
-                .post(RequestBody.create(null, ""))
+                .post(RequestBody.create(new byte[0]))
                 .addHeader(REFERER, Camsoda.BASE_URI + '/' + getName())
                 .addHeader(USER_AGENT, Config.getInstance().getSettings().httpUserAgent)
                 .addHeader(ACCEPT, MIMETYPE_APPLICATION_JSON)
diff --git a/common/src/main/java/ctbrec/sites/chaturbate/ChaturbateModel.java b/common/src/main/java/ctbrec/sites/chaturbate/ChaturbateModel.java
index db37f656..9a9cd01f 100644
--- a/common/src/main/java/ctbrec/sites/chaturbate/ChaturbateModel.java
+++ b/common/src/main/java/ctbrec/sites/chaturbate/ChaturbateModel.java
@@ -220,7 +220,7 @@ public class ChaturbateModel extends AbstractModel { // NOSONAR
             url = getSite().getBaseUrl() + "/follow/unfollow/" + getName() + "/";
         }
 
-        RequestBody body = RequestBody.create(null, new byte[0]);
+        RequestBody body = RequestBody.create(new byte[0]);
         req = new Request.Builder()
                 .url(url)
                 .method("POST", body)
diff --git a/common/src/main/java/ctbrec/sites/streamate/StreamateHttpClient.java b/common/src/main/java/ctbrec/sites/streamate/StreamateHttpClient.java
index dedb01cd..08c5425c 100644
--- a/common/src/main/java/ctbrec/sites/streamate/StreamateHttpClient.java
+++ b/common/src/main/java/ctbrec/sites/streamate/StreamateHttpClient.java
@@ -29,6 +29,7 @@ public class StreamateHttpClient extends HttpClient {
     private static final String SAKEY_KEY = "sakey";
 
     private static final Logger LOG = LoggerFactory.getLogger(StreamateHttpClient.class);
+    public static final MediaType JSON = MediaType.parse("application/json; charset=utf-8");
 
     private Long userId;
     private String saKey = "";
@@ -106,7 +107,7 @@ public class StreamateHttpClient extends HttpClient {
         loginRequest.put("siteId", 1);
         loginRequest.put("siteType", "premium");
         loginRequest.put("tzOffsetMinutes", 0);
-        RequestBody body = RequestBody.create(MediaType.parse("application/json"), loginRequest.toString());
+        RequestBody body = RequestBody.Companion.create(loginRequest.toString(), JSON);
         Request login = newRequestBuilder()
                 .url(Streamate.BASE_URL + "/api/member/login")
                 .post(body)
diff --git a/common/src/main/java/ctbrec/sites/streamate/StreamateModel.java b/common/src/main/java/ctbrec/sites/streamate/StreamateModel.java
index 30a46261..43fe8ade 100644
--- a/common/src/main/java/ctbrec/sites/streamate/StreamateModel.java
+++ b/common/src/main/java/ctbrec/sites/streamate/StreamateModel.java
@@ -2,6 +2,7 @@ package ctbrec.sites.streamate;
 
 import static ctbrec.Model.State.*;
 import static ctbrec.io.HttpConstants.*;
+import static ctbrec.sites.streamate.StreamateHttpClient.*;
 
 import java.io.IOException;
 import java.util.ArrayList;
@@ -25,7 +26,6 @@ import ctbrec.Config;
 import ctbrec.NotImplementedExcetion;
 import ctbrec.io.HttpException;
 import ctbrec.recorder.download.StreamSource;
-import okhttp3.MediaType;
 import okhttp3.Request;
 import okhttp3.RequestBody;
 import okhttp3.Response;
@@ -204,7 +204,7 @@ public class StreamateModel extends AbstractModel {
         requestParams.put("pid", id);
         requestParams.put("domain", "streamate.com");
         requestParams.put("fav", follow);
-        RequestBody body = RequestBody.create(MediaType.parse("application/json"), requestParams.toString());
+        RequestBody body = RequestBody.Companion.create(requestParams.toString(), JSON);
 
         String url = site.getBaseUrl() + "/ajax/fav-notify.php?userid="+userId+"&sakey="+saKey+"&pid="+id+"&fav="+follow+"&domain=streamate.com";
         Request request = new Request.Builder()
diff --git a/common/src/main/java/ctbrec/sites/stripchat/StripchatHttpClient.java b/common/src/main/java/ctbrec/sites/stripchat/StripchatHttpClient.java
index 5702459b..2b3fd2fe 100644
--- a/common/src/main/java/ctbrec/sites/stripchat/StripchatHttpClient.java
+++ b/common/src/main/java/ctbrec/sites/stripchat/StripchatHttpClient.java
@@ -20,6 +20,7 @@ import okhttp3.Response;
 public class StripchatHttpClient extends HttpClient {
 
     private static final Logger LOG = LoggerFactory.getLogger(StripchatHttpClient.class);
+    public static final MediaType JSON = MediaType.parse("application/json; charset=utf-8");
 
     private long userId;
     private String csrfToken;
@@ -61,7 +62,7 @@ public class StripchatHttpClient extends HttpClient {
         requestParams.put("csrfToken", csrfToken);
         requestParams.put("csrfTimestamp", csrfTimestamp);
         requestParams.put("csrfNotifyTimestamp", csrfNotifyTimestamp);
-        RequestBody body = RequestBody.create(MediaType.parse("application/json"), requestParams.toString());
+        RequestBody body = RequestBody.Companion.create(requestParams.toString(), JSON);
         Request request = new Request.Builder()
                 .url(url)
                 .header(ACCEPT, MIMETYPE_APPLICATION_JSON)
diff --git a/common/src/main/java/ctbrec/sites/stripchat/StripchatModel.java b/common/src/main/java/ctbrec/sites/stripchat/StripchatModel.java
index 4e657af3..446c9164 100644
--- a/common/src/main/java/ctbrec/sites/stripchat/StripchatModel.java
+++ b/common/src/main/java/ctbrec/sites/stripchat/StripchatModel.java
@@ -2,6 +2,7 @@ package ctbrec.sites.stripchat;
 
 import static ctbrec.Model.State.*;
 import static ctbrec.io.HttpConstants.*;
+import static ctbrec.sites.stripchat.StripchatHttpClient.*;
 
 import java.io.IOException;
 import java.util.ArrayList;
@@ -25,7 +26,6 @@ import ctbrec.AbstractModel;
 import ctbrec.Config;
 import ctbrec.io.HttpException;
 import ctbrec.recorder.download.StreamSource;
-import okhttp3.MediaType;
 import okhttp3.Request;
 import okhttp3.RequestBody;
 import okhttp3.Response;
@@ -183,7 +183,7 @@ public class StripchatModel extends AbstractModel {
         requestParams.put("csrfToken", client.getCsrfToken());
         requestParams.put("csrfTimestamp", client.getCsrfTimestamp());
         requestParams.put("csrfNotifyTimestamp", client.getCsrfNotifyTimestamp());
-        RequestBody body = RequestBody.create(MediaType.parse("application/json"), requestParams.toString());
+        RequestBody body = RequestBody.Companion.create(requestParams.toString(), JSON);
         Request request = new Request.Builder()
                 .url(url)
                 .header(ACCEPT, "*/*")
@@ -218,7 +218,7 @@ public class StripchatModel extends AbstractModel {
         requestParams.put("csrfToken", client.getCsrfToken());
         requestParams.put("csrfTimestamp", client.getCsrfTimestamp());
         requestParams.put("csrfNotifyTimestamp", client.getCsrfNotifyTimestamp());
-        RequestBody body = RequestBody.create(MediaType.parse("application/json"), requestParams.toString());
+        RequestBody body = RequestBody.Companion.create(requestParams.toString(), JSON);
         Request request = new Request.Builder()
                 .url(url)
                 .header(ACCEPT, MIMETYPE_APPLICATION_JSON)
diff --git a/master/pom.xml b/master/pom.xml
index 744ed8ed..4450e013 100644
--- a/master/pom.xml
+++ b/master/pom.xml
@@ -58,7 +58,7 @@
 			<dependency>
 				<groupId>com.squareup.okhttp3</groupId>
 				<artifactId>okhttp</artifactId>
-				<version>3.10.0</version>
+				<version>4.9.0</version>
 			</dependency>
 			<dependency>
 				<groupId>com.squareup.moshi</groupId>