diff --git a/network/src/main/java/de/muehlencord/shared/network/http/HttpLayer.java b/network/src/main/java/de/muehlencord/shared/network/http/HttpLayer.java
index 4c691d5..b2a0043 100644
--- a/network/src/main/java/de/muehlencord/shared/network/http/HttpLayer.java
+++ b/network/src/main/java/de/muehlencord/shared/network/http/HttpLayer.java
@@ -10,12 +10,12 @@ import java.net.MalformedURLException;
 import java.net.URL;
 import java.net.URLConnection;
 import java.net.URLEncoder;
-import java.util.HashMap;
 import java.util.Iterator;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.Locale;
 import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
 import org.apache.log4j.Logger;
 
 /**
@@ -50,7 +50,7 @@ public class HttpLayer {
      */
     public void post(String parameter, String message)
             throws MessageNotSendException {
-        Map<String, String[]> parameterMap = new HashMap<>();
+        Map<String, String[]> parameterMap = new ConcurrentHashMap<>();
         String[] valueArray = {message};
         parameterMap.put(parameter, valueArray);
         post(parameterMap);
diff --git a/network/src/main/java/de/muehlencord/shared/network/whois/AbstractWhoisParser.java b/network/src/main/java/de/muehlencord/shared/network/whois/AbstractWhoisParser.java
index f97066d..9e59372 100644
--- a/network/src/main/java/de/muehlencord/shared/network/whois/AbstractWhoisParser.java
+++ b/network/src/main/java/de/muehlencord/shared/network/whois/AbstractWhoisParser.java
@@ -1,12 +1,7 @@
-/*
- * To change this template, choose Tools | Templates
- * and open the template in the editor.
- */
 package de.muehlencord.shared.network.whois;
 
-import de.muehlencord.shared.network.whois.WhoisParser;
-import java.util.HashMap;
 import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
 
 /**
  *
@@ -15,7 +10,7 @@ import java.util.Map;
 public abstract class AbstractWhoisParser implements WhoisParser {
 
     protected Map<String, String> getValueMap(String blockString) {
-        Map<String, String> returnMap = new HashMap<>();
+        Map<String, String> returnMap = new ConcurrentHashMap<>();
 
         String[] lines = blockString.split("\n");
         for (String line : lines) {
diff --git a/network/src/main/java/de/muehlencord/shared/network/whois/NetworkInformation.java b/network/src/main/java/de/muehlencord/shared/network/whois/NetworkInformation.java
index 56e82a0..bd7fa06 100644
--- a/network/src/main/java/de/muehlencord/shared/network/whois/NetworkInformation.java
+++ b/network/src/main/java/de/muehlencord/shared/network/whois/NetworkInformation.java
@@ -7,6 +7,8 @@ import java.io.Serializable;
  * @author jomu
  */
 public class NetworkInformation implements Serializable {
+    /** the serial version uid */
+    private static final long serialVersionUID = 5099628868075224118L;
 
     // private String network;
     private String netname;
diff --git a/sharepoint/api/src/main/java/de/muehlencord/shared/sharepoint/api/lists/SPList.java b/sharepoint/api/src/main/java/de/muehlencord/shared/sharepoint/api/lists/SPList.java
index 983c92e..1ab2153 100644
--- a/sharepoint/api/src/main/java/de/muehlencord/shared/sharepoint/api/lists/SPList.java
+++ b/sharepoint/api/src/main/java/de/muehlencord/shared/sharepoint/api/lists/SPList.java
@@ -19,9 +19,9 @@ import java.net.MalformedURLException;
 import java.security.KeyManagementException;
 import java.security.NoSuchAlgorithmException;
 import java.util.ArrayList;
-import java.util.HashMap;
 import java.util.LinkedList;
 import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
 import javax.xml.bind.JAXBException;
 import javax.xml.parsers.ParserConfigurationException;
 import javax.xml.ws.BindingProvider;
@@ -198,7 +198,7 @@ public class SPList extends SPJaxbObject<List> {
         java.util.List<java.util.List<String>> listItems = getListItems(listColumnNames, rowLimit);
 
         // convert to map from value to <ID>;#<value>        
-        Map<String, String> returnMap = new HashMap<>();
+        Map<String, String> returnMap = new ConcurrentHashMap<>();
 
         for (java.util.List<String> row : listItems) {
             String rowId = row.get(0);