diff --git a/packages/api/src/base/util.ts b/packages/api/src/base/util.ts
index ee17f4b1a5..053d5c5d13 100644
--- a/packages/api/src/base/util.ts
+++ b/packages/api/src/base/util.ts
@@ -4,6 +4,7 @@
 import type { ApiInterfaceRx } from '@polkadot/api/types';
 import type { bool } from '@polkadot/types';
 import type { Releases } from '@polkadot/types/interfaces';
+import type { InterfaceTypes } from '@polkadot/types/types';
 
 import { combineLatest, Observable, of } from '@polkadot/x-rxjs';
 import { map, take } from '@polkadot/x-rxjs/operators';
@@ -11,7 +12,11 @@ import { map, take } from '@polkadot/x-rxjs/operators';
 // the order and types needs to map with the all array setup below
 type Extracted = [bool | null, bool | null, Releases | null];
 
-interface DetectedTypes {
+type DetectedKeys = keyof Pick<InterfaceTypes, 'AccountInfo' | 'ValidatorPrefs'>;
+
+type DetectedValues = keyof InterfaceTypes;
+
+interface DetectedTypes extends Record<DetectedKeys, DetectedValues> {
   AccountInfo: 'AccountInfoWithRefCount' | 'AccountInfoWithProviders',
   ValidatorPrefs: 'ValidatorPrefsWithBlocked' | 'ValidatorPrefsWithCommission';
 }
diff --git a/packages/types/src/create/registry.ts b/packages/types/src/create/registry.ts
index f88c34a33f..42719016e9 100644
--- a/packages/types/src/create/registry.ts
+++ b/packages/types/src/create/registry.ts
@@ -316,6 +316,7 @@ export class TypeRegistry implements Registry {
       this.#classes.set(arg1.name, arg1);
     } else if (isString(arg1)) {
       assert(isFunction(arg2), `Expected class definition passed to '${arg1}' registration`);
+      assert(arg1 !== arg2.toString(), `Unable to register circular ${arg1} === ${arg1}`);
 
       this.#classes.set(arg1, arg2);
     } else {
@@ -333,6 +334,8 @@ export class TypeRegistry implements Registry {
           ? type
           : JSON.stringify(type);
 
+        assert(name !== def, `Unable to register circular ${name} === ${def}`);
+
         // we already have this type, remove the classes registered for it
         if (this.#classes.has(name)) {
           this.#classes.delete(name);