diff --git a/src/caip-types.ts b/src/caip-types.ts
index b20076134..443f99c29 100644
--- a/src/caip-types.ts
+++ b/src/caip-types.ts
@@ -142,6 +142,15 @@ export enum KnownCaipNamespace {
   Wallet = 'wallet',
 }
 
+/**
+ * A CAIP-2 chain ID that is guaranteed to have a known CAIP namespace
+ * (@see {@link KnownCaipNamespace}).
+ *
+ * This is a narrower, more type-safe alternative to {@link CaipChainId} for use cases
+ * where the chain namespace must be one of the known standards.
+ */
+export type KnownCaipNamespacedChainId = `${KnownCaipNamespace}:${string}`;
+
 /**
  * Check if the given value is a {@link CaipChainId}.
  *