diff --git a/jenkins-client/src/main/java/com/offbytwo/jenkins/client/JenkinsHttpClient.java b/jenkins-client/src/main/java/com/offbytwo/jenkins/client/JenkinsHttpClient.java
index 4eadc5c9..d70bdd90 100755
--- a/jenkins-client/src/main/java/com/offbytwo/jenkins/client/JenkinsHttpClient.java
+++ b/jenkins-client/src/main/java/com/offbytwo/jenkins/client/JenkinsHttpClient.java
@@ -12,6 +12,7 @@
 import com.offbytwo.jenkins.model.BaseModel;
 import com.offbytwo.jenkins.model.Crumb;
 import com.offbytwo.jenkins.model.ExtractHeader;
+import java.nio.charset.StandardCharsets;
 import net.sf.json.JSONObject;
 import org.apache.commons.io.IOUtils;
 import org.apache.commons.lang.StringUtils;
@@ -45,7 +46,6 @@
 import java.io.IOException;
 import java.io.InputStream;
 import java.net.URI;
-import java.nio.ByteBuffer;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
@@ -298,7 +298,8 @@ public void post_form(String path, Map<String, String> data, boolean crumbFlag)
 
             queryParams.add("json=" + EncodingUtils.formParameter(JSONObject.fromObject(data).toString()));
             String value = mapper.writeValueAsString(data);
-            StringEntity stringEntity = new StringEntity(value, ContentType.APPLICATION_FORM_URLENCODED);
+            StringEntity stringEntity = new StringEntity(value, ContentType.create(ContentType.APPLICATION_FORM_URLENCODED.getMimeType(),
+                StandardCharsets.UTF_8));
             request = new HttpPost(UrlUtils.toNoApiUri(uri, context, path) + StringUtils.join(queryParams, "&"));
             request.setEntity(stringEntity);
         } else {
@@ -325,7 +326,7 @@ public void post_form(String path, Map<String, String> data, boolean crumbFlag)
     public HttpResponse post_form_with_result(String path, List<NameValuePair> data, boolean crumbFlag) throws IOException {
         HttpPost request;
         if (data != null) {
-            UrlEncodedFormEntity urlEncodedFormEntity = new UrlEncodedFormEntity(data);
+            UrlEncodedFormEntity urlEncodedFormEntity = new UrlEncodedFormEntity(data,StandardCharsets.UTF_8);
             request = new HttpPost(UrlUtils.toNoApiUri(uri, context, path));
             request.setEntity(urlEncodedFormEntity);
         } else {
@@ -355,7 +356,7 @@ public String post_xml(String path, String xml_data, boolean crumbFlag) throws I
         handleCrumbFlag(crumbFlag, request);
 
         if (xml_data != null) {
-            request.setEntity(new StringEntity(xml_data, ContentType.create("text/xml", "utf-8")));
+            request.setEntity(new StringEntity(xml_data, ContentType.create(ContentType.TEXT_XML.getMimeType(), StandardCharsets.UTF_8)));
         }
         HttpResponse response = client.execute(request, localContext);
         jenkinsVersion = ResponseUtils.getJenkinsVersion(response);
@@ -373,7 +374,7 @@ public String post_xml(String path, String xml_data, boolean crumbFlag) throws I
      */
     @Override
     public String post_text(String path, String textData, boolean crumbFlag) throws IOException {
-        return post_text(path, textData, ContentType.DEFAULT_TEXT, crumbFlag);
+        return post_text(path, textData, ContentType.create(ContentType.TEXT_PLAIN.getMimeType(), StandardCharsets.UTF_8), crumbFlag);
     }
 
     /**