diff --git a/base/src/commonMain/kotlin/de/staropensource/engine/base/implementable/PlatformData.kt b/base/src/commonMain/kotlin/de/staropensource/engine/base/implementable/PlatformData.kt
index 833b390..2131b8f 100644
--- a/base/src/commonMain/kotlin/de/staropensource/engine/base/implementable/PlatformData.kt
+++ b/base/src/commonMain/kotlin/de/staropensource/engine/base/implementable/PlatformData.kt
@@ -19,11 +19,15 @@
 
 package de.staropensource.engine.base.implementable
 
+import org.jetbrains.annotations.ApiStatus
+
 /**
  * Interface for platform-specific data.
  *
  * @since v1-alpha10
  */
+@ApiStatus.Internal
+@ApiStatus.NonExtendable
 interface PlatformData {
     /**
      * Contains platform-specific data.