diff --git a/packages/types/src/create/registry.ts b/packages/types/src/create/registry.ts
index 7b20ae36e9..a3a982c2c3 100644
--- a/packages/types/src/create/registry.ts
+++ b/packages/types/src/create/registry.ts
@@ -193,6 +193,10 @@ export class TypeRegistry implements Registry {
     return this.#knownTypes;
   }
 
+  public get unknownTypes (): string[] {
+    return [...this.#unknownTypes.keys()];
+  }
+
   public get signedExtensions (): string[] {
     return this.#signedExtensions;
   }
diff --git a/packages/types/src/types/registry.ts b/packages/types/src/types/registry.ts
index c9c30e081c..45c970df0c 100644
--- a/packages/types/src/types/registry.ts
+++ b/packages/types/src/types/registry.ts
@@ -98,6 +98,7 @@ export interface Registry {
   readonly chainSS58: number | undefined;
   readonly chainTokens: string[];
   readonly knownTypes: RegisteredTypes;
+  readonly unknownTypes: string[];
   readonly signedExtensions: string[];
 
   findMetaCall (callIndex: Uint8Array): CallFunction;