diff --git a/packages/controller-utils/CHANGELOG.md b/packages/controller-utils/CHANGELOG.md
index c1b196e62af..daa01a7c5e4 100644
--- a/packages/controller-utils/CHANGELOG.md
+++ b/packages/controller-utils/CHANGELOG.md
@@ -7,6 +7,11 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Added
+
+- Update `onDegraded` in `createServicePolicy` so that its event payload now includes an `error` property which can be used to access the error produced by the last request when the maximum number of retries is exceeded ([#6188](https://github.com/MetaMask/core/pull/6188))
+  - This `error` property will be `undefined` if the degraded event merely represents a slow request
+
 ## [11.11.0]
 
 ### Added
diff --git a/packages/controller-utils/src/create-service-policy.ts b/packages/controller-utils/src/create-service-policy.ts
index e2028b42dce..fbce1ed88d8 100644
--- a/packages/controller-utils/src/create-service-policy.ts
+++ b/packages/controller-utils/src/create-service-policy.ts
@@ -14,6 +14,7 @@ import {
 import type {
   CircuitBreakerPolicy,
   Event as CockatielEvent,
+  FailureReason,
   IBackoffFactory,
   IPolicy,
   Policy,
@@ -95,7 +96,7 @@ export type ServicePolicy = IPolicy & {
    * never succeeds before the retry policy gives up and before the maximum
    * number of consecutive failures has been reached.
    */
-  onDegraded: CockatielEvent<void>;
+  onDegraded: CockatielEvent<FailureReason<unknown> | void>;
   /**
    * A function which will be called by the retry policy each time the service
    * fails and the policy kicks off a timer to re-run the service. This is
@@ -229,10 +230,11 @@ export function createServicePolicy(
   });
   const onBreak = circuitBreakerPolicy.onBreak.bind(circuitBreakerPolicy);
 
-  const onDegradedEventEmitter = new CockatielEventEmitter<void>();
-  retryPolicy.onGiveUp(() => {
+  const onDegradedEventEmitter =
+    new CockatielEventEmitter<FailureReason<unknown> | void>();
+  retryPolicy.onGiveUp((data) => {
     if (circuitBreakerPolicy.state === CircuitState.Closed) {
-      onDegradedEventEmitter.emit();
+      onDegradedEventEmitter.emit(data);
     }
   });
   retryPolicy.onSuccess(({ duration }) => {
diff --git a/packages/network-controller/CHANGELOG.md b/packages/network-controller/CHANGELOG.md
index 4ec2e5b1b45..a07f31d1b9b 100644
--- a/packages/network-controller/CHANGELOG.md
+++ b/packages/network-controller/CHANGELOG.md
@@ -7,6 +7,11 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Added
+
+- The object in the `NetworkController:rpcEndpointDegraded` event payload now includes an `error` property, which can be used to access the error produced by the last request when the maximum number of retries is exceeded ([#6188](https://github.com/MetaMask/core/pull/6188))
+  - This `error` property will be `undefined` if the degraded event merely represents a slow request
+
 ### Changed
 
 - Bump `@metamask/base-controller` from `^8.0.1` to `^8.1.0` ([#6284](https://github.com/MetaMask/core/pull/6284))
diff --git a/packages/network-controller/src/NetworkController.ts b/packages/network-controller/src/NetworkController.ts
index d23f6d55aae..ceaef81f810 100644
--- a/packages/network-controller/src/NetworkController.ts
+++ b/packages/network-controller/src/NetworkController.ts
@@ -470,6 +470,7 @@ export type NetworkControllerRpcEndpointDegradedEvent = {
     {
       chainId: Hex;
       endpointUrl: string;
+      error: unknown;
     },
   ];
 };
diff --git a/packages/network-controller/src/create-network-client.ts b/packages/network-controller/src/create-network-client.ts
index c6388ae3c18..7ac7f920dc9 100644
--- a/packages/network-controller/src/create-network-client.ts
+++ b/packages/network-controller/src/create-network-client.ts
@@ -111,10 +111,18 @@ export function createNetworkClient({
       error,
     });
   });
-  rpcServiceChain.onDegraded(({ endpointUrl }) => {
+  rpcServiceChain.onDegraded(({ endpointUrl, ...rest }) => {
+    let error: unknown;
+    if ('error' in rest) {
+      error = rest.error;
+    } else if ('value' in rest) {
+      error = rest.value;
+    }
+
     messenger.publish('NetworkController:rpcEndpointDegraded', {
       chainId: configuration.chainId,
       endpointUrl,
+      error,
     });
   });
   rpcServiceChain.onRetry(({ endpointUrl, attempt }) => {
diff --git a/packages/network-controller/src/rpc-service/rpc-service.ts b/packages/network-controller/src/rpc-service/rpc-service.ts
index 383b98d3605..037429364ac 100644
--- a/packages/network-controller/src/rpc-service/rpc-service.ts
+++ b/packages/network-controller/src/rpc-service/rpc-service.ts
@@ -361,8 +361,8 @@ export class RpcService implements AbstractRpcService {
       { endpointUrl: string }
     >,
   ) {
-    return this.#policy.onDegraded(() => {
-      listener({ endpointUrl: this.endpointUrl.toString() });
+    return this.#policy.onDegraded((data) => {
+      listener({ ...(data ?? {}), endpointUrl: this.endpointUrl.toString() });
     });
   }
 
diff --git a/packages/network-controller/src/rpc-service/shared.ts b/packages/network-controller/src/rpc-service/shared.ts
index 68e4c78b250..e33ae6129ad 100644
--- a/packages/network-controller/src/rpc-service/shared.ts
+++ b/packages/network-controller/src/rpc-service/shared.ts
@@ -9,8 +9,5 @@ export type FetchOptions = RequestInit;
  */
 export type AddToCockatielEventData<EventListener, AdditionalData> =
   EventListener extends (data: infer Data) => void
-    ? // Prevent Data from being split if it's a type union
-      [Data] extends [void]
-      ? (data: AdditionalData) => void
-      : (data: Data & AdditionalData) => void
+    ? (data: Data extends void ? AdditionalData : Data & AdditionalData) => void
     : never;