diff --git a/src/main/java/uulm/teamname/marvelous/gamelibrary/json/ingame/EntityDeserializer.java b/src/main/java/uulm/teamname/marvelous/gamelibrary/json/ingame/EntityDeserializer.java
index 6830f70..1c9b9a8 100644
--- a/src/main/java/uulm/teamname/marvelous/gamelibrary/json/ingame/EntityDeserializer.java
+++ b/src/main/java/uulm/teamname/marvelous/gamelibrary/json/ingame/EntityDeserializer.java
@@ -21,7 +21,8 @@ public class EntityDeserializer extends JsonDeserializer<Entity> {
         Rock
     }
 
-    private final ObjectMapper mapper = new ObjectMapper();
+    // static so that no reinitializations are needed
+    private static final ObjectMapper mapper = new ObjectMapper();
 
     @Override
     public Entity deserialize(JsonParser p, DeserializationContext ctxt) throws IOException {
diff --git a/src/main/java/uulm/teamname/marvelous/gamelibrary/json/ingame/EventDeserializer.java b/src/main/java/uulm/teamname/marvelous/gamelibrary/json/ingame/EventDeserializer.java
index dd33762..a288cc1 100644
--- a/src/main/java/uulm/teamname/marvelous/gamelibrary/json/ingame/EventDeserializer.java
+++ b/src/main/java/uulm/teamname/marvelous/gamelibrary/json/ingame/EventDeserializer.java
@@ -22,7 +22,8 @@ import java.util.HashMap;
 
 public class EventDeserializer extends JsonDeserializer<Event> {
 
-    private final ObjectMapper mapper = new ObjectMapper();
+    // static so that no reinitializations are needed
+    private static final ObjectMapper mapper = new ObjectMapper();
 
     @Override
     public Event deserialize(JsonParser p, DeserializationContext ctxt) throws IOException {
diff --git a/src/main/java/uulm/teamname/marvelous/gamelibrary/json/ingame/IntVector2Deserializer.java b/src/main/java/uulm/teamname/marvelous/gamelibrary/json/ingame/IntVector2Deserializer.java
index 5741a9c..a01af72 100644
--- a/src/main/java/uulm/teamname/marvelous/gamelibrary/json/ingame/IntVector2Deserializer.java
+++ b/src/main/java/uulm/teamname/marvelous/gamelibrary/json/ingame/IntVector2Deserializer.java
@@ -13,7 +13,8 @@ import java.io.IOException;
 
 public class IntVector2Deserializer extends JsonDeserializer<IntVector2> {
 
-    ObjectMapper mapper = new ObjectMapper();
+    // static so that no reinitializations are needed
+    private static final ObjectMapper mapper = new ObjectMapper();
 
     @Override
     public IntVector2 deserialize(JsonParser p, DeserializationContext ctxt) throws IOException {