diff --git a/src/core/Thing.ts b/src/core/Thing.ts
index c90baa7f..f8dfc8f7 100644
--- a/src/core/Thing.ts
+++ b/src/core/Thing.ts
@@ -222,7 +222,7 @@ export class SCThingMeta implements SCMetaTranslations<SCThing> {
   /**
    * Set type definiton for singleton instance
    */
-  protected static _instance: SCThingMeta;
+  protected static _instance = new Map<string, unknown>();
 
   /**
    * Translations of fields
@@ -268,8 +268,10 @@ export class SCThingMeta implements SCMetaTranslations<SCThing> {
    * Function to retrieve typed singleton instance
    */
   public static getInstance<T extends SCThingMeta>(): T {
-    const typedThis = this as any as typeof SCThingMeta;
-    return (typedThis._instance || (typedThis._instance = new this())) as T;
+    if (!this._instance.has(this.name)) {
+      this._instance.set(this.name, new this());
+    }
+    return this._instance.get(this.name) as T;
   }
 
   protected constructor() {}
diff --git a/src/core/things/Diff.ts b/src/core/things/Diff.ts
index e2b9991f..44be0293 100644
--- a/src/core/things/Diff.ts
+++ b/src/core/things/Diff.ts
@@ -64,11 +64,6 @@ export interface SCDiff extends SCDiffWithoutReferences {
  * Meta information about a diff
  */
 export class SCDiffMeta extends SCThingMeta implements SCMetaTranslations<SCDiff> {
-  /**
-   * Set type definiton for singleton instance
-   */
-  protected static _instance: SCThingMeta;
-
   /**
    * Translations of fields
    */