diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1a2fa282c..af214104e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Changed
+
+- Make `KnownCaipNamespacedChainId` type generic over `Namespace` type parameter ([#262](https://github.com/MetaMask/utils/pull/262))
+
 ## [11.5.0]
 
 ### Added
diff --git a/src/caip-types.ts b/src/caip-types.ts
index 443f99c29..a48c7f2f1 100644
--- a/src/caip-types.ts
+++ b/src/caip-types.ts
@@ -148,8 +148,12 @@ export enum 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.
+ *
+ * @template Namespace - The namespace of the CAIP-2 chain ID. Must be a known namespace specified in {@link KnownCaipNamespace}.
  */
-export type KnownCaipNamespacedChainId = `${KnownCaipNamespace}:${string}`;
+export type KnownCaipNamespacedChainId<
+  Namespace extends `${KnownCaipNamespace}` = `${KnownCaipNamespace}`,
+> = `${Namespace}:${string}`;
 
 /**
  * Check if the given value is a {@link CaipChainId}.