diff --git a/src/client/api/configuration.ts b/src/client/api/configuration.ts
index d12978a..6b90c64 100644
--- a/src/client/api/configuration.ts
+++ b/src/client/api/configuration.ts
@@ -2,7 +2,7 @@ import { Observable, Subscription } from 'rxjs'
 import { createProxyAndHandleRequests } from '../../common/proxy'
 import { ExtConfigurationAPI } from '../../extension/api/configuration'
 import { ConfigurationUpdateParams } from '../../protocol'
-import { Connection } from '../../protocol/jsonrpc2/connection'
+import { Connection, ConnectionError, ConnectionErrors } from '../../protocol/jsonrpc2/connection'
 
 /** @internal */
 export interface ClientConfigurationAPI {
@@ -26,7 +26,14 @@ export class ClientConfiguration<C> implements ClientConfigurationAPI {
 
         this.subscriptions.add(
             environmentConfiguration.subscribe(config => {
-                this.proxy.$acceptConfigurationData(config)
+                this.proxy.$acceptConfigurationData(config).catch(error => {
+                    if (error instanceof ConnectionError && error.code === ConnectionErrors.Unsubscribed) {
+                        // This error was probably caused by the user disabling
+                        // an extension, which is a normal occurrence.
+                        return
+                    }
+                    throw error
+                })
             })
         )
     }
diff --git a/src/extension/api/configuration.ts b/src/extension/api/configuration.ts
index 70f9bb1..931fa2f 100644
--- a/src/extension/api/configuration.ts
+++ b/src/extension/api/configuration.ts
@@ -36,7 +36,7 @@ class ExtConfigurationSection<C extends object> implements sourcegraph.Configura
  * @template C - The configuration schema.
  */
 export interface ExtConfigurationAPI<C> {
-    $acceptConfigurationData(data: Readonly<C>): void
+    $acceptConfigurationData(data: Readonly<C>): Promise<void>
 }
 
 /**
@@ -48,8 +48,9 @@ export class ExtConfiguration<C extends ConfigurationCascade<any>> implements Ex
 
     constructor(private proxy: ClientConfigurationAPI) {}
 
-    public $acceptConfigurationData(data: Readonly<C>): void {
+    public $acceptConfigurationData(data: Readonly<C>): Promise<void> {
         this.data.next(Object.freeze(data))
+        return Promise.resolve()
     }
 
     public get(): sourcegraph.Configuration<C> {
diff --git a/src/protocol/jsonrpc2/connection.ts b/src/protocol/jsonrpc2/connection.ts
index 640ea4f..c403f78 100644
--- a/src/protocol/jsonrpc2/connection.ts
+++ b/src/protocol/jsonrpc2/connection.ts
@@ -48,7 +48,7 @@ const NullLogger: Logger = Object.freeze({
     },
 })
 
-enum ConnectionErrors {
+export enum ConnectionErrors {
     /**
      * The connection is closed.
      */
@@ -63,7 +63,7 @@ enum ConnectionErrors {
     AlreadyListening = 3,
 }
 
-class ConnectionError extends Error {
+export class ConnectionError extends Error {
     public readonly code: ConnectionErrors
 
     constructor(code: ConnectionErrors, message: string) {
@@ -632,9 +632,15 @@ function _createConnection(transports: MessageTransports, logger: Logger, strate
             }
             state = ConnectionState.Unsubscribed
             unsubscribeEmitter.fire(undefined)
-            const error = new Error('Connection got unsubscribed.')
             for (const key of Object.keys(responsePromises)) {
-                responsePromises[key].reject(error)
+                responsePromises[key].reject(
+                    new ConnectionError(
+                        ConnectionErrors.Unsubscribed,
+                        `The underlying JSON-RPC connection got unsubscribed while responding to this ${
+                            responsePromises[key].method
+                        } request.`
+                    )
+                )
             }
             responsePromises = Object.create(null)
             requestTokens = Object.create(null)