diff --git a/Core/src/main/java/fr/altarik/toolbox/core/data/DataTracker.java b/Core/src/main/java/fr/altarik/toolbox/core/data/DataTracker.java
index a655928..2e625c5 100644
--- a/Core/src/main/java/fr/altarik/toolbox/core/data/DataTracker.java
+++ b/Core/src/main/java/fr/altarik/toolbox/core/data/DataTracker.java
@@ -11,7 +11,13 @@ public class DataTracker {
     }
 
     public void startTracking(TrackedData data) {
-        trackedData.put(data, data.defaultValue());
+        String v = trackedData.get(data);
+        if(v == null) {
+            trackedData.put(data, data.defaultValue());
+        } else {
+            throw new IllegalArgumentException("Data " + data.name() + " has already been initialized");
+        }
+
     }
 
     public String getOrDefault(TrackedData data) {
@@ -21,7 +27,7 @@ public class DataTracker {
     public void set(TrackedData data, String value) {
         String v = trackedData.get(data);
         if(v != null) {
-            trackedData.putIfAbsent(data, value);
+            trackedData.put(data, value);
         } else {
             throw new IllegalArgumentException("Data " + data.name() + " is not tracked, please initialize it with DataTracker#startTracking(TrackedData, String) first");
         }
diff --git a/gradle.properties b/gradle.properties
index c093845..f7f7fb2 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -8,5 +8,5 @@ loader_version=0.14.14
 fabric_version=0.75.1+1.19.3
 
 maven_group=fr.altarik.toolbox
-maven_version=4.2.0-SNAPSHOT
+maven_version=4.2.1-SNAPSHOT
 repo_username=Altarik