diff --git a/src/controllers/ExtensionController.ts b/src/controllers/ExtensionController.ts
index c057b438..55f28d52 100644
--- a/src/controllers/ExtensionController.ts
+++ b/src/controllers/ExtensionController.ts
@@ -345,7 +345,10 @@ export class ExtensionController implements Disposable {
     };
 
     this._coreClientCache = new URLMap();
+    this._context.subscriptions.push(this._coreClientCache);
+
     this._dheClientCache = new URLMap();
+    this._context.subscriptions.push(this._dheClientCache);
 
     this._panelService = new PanelService();
     this._context.subscriptions.push(this._panelService);
diff --git a/src/services/DheService.ts b/src/services/DheService.ts
index 50dafde2..dc5e805a 100644
--- a/src/services/DheService.ts
+++ b/src/services/DheService.ts
@@ -256,8 +256,10 @@ export class DheService implements IDheService {
     const querySerials = [...this._querySerialSet];
 
     this._querySerialSet.clear();
-    this._workerInfoMap.clear();
 
-    await this._disposeQueries(querySerials);
+    await Promise.all([
+      this._workerInfoMap.dispose(),
+      this._disposeQueries(querySerials),
+    ]);
   };
 }
diff --git a/src/services/PanelService.ts b/src/services/PanelService.ts
index 30bd67bf..42b6036b 100644
--- a/src/services/PanelService.ts
+++ b/src/services/PanelService.ts
@@ -35,9 +35,12 @@ export class PanelService implements IPanelService, Disposable {
    * Cleanup resources.
    */
   dispose = async (): Promise<void> => {
-    this._cnPanelMap.clear();
-    this._cnVariableMap.clear();
     this._onDidUpdate.dispose();
+
+    await Promise.all([
+      this._cnPanelMap.dispose(),
+      this._cnVariableMap.dispose(),
+    ]);
   };
 
   /**
diff --git a/src/services/SerializedKeyMap.ts b/src/services/SerializedKeyMap.ts
index cb291664..e097583a 100644
--- a/src/services/SerializedKeyMap.ts
+++ b/src/services/SerializedKeyMap.ts
@@ -1,5 +1,6 @@
 import * as vscode from 'vscode';
 import type { Disposable } from '../types';
+import { isDisposable } from '../util';
 
 /**
  * Base class for Maps that need to store their keys as serialized string values
@@ -42,8 +43,20 @@ export abstract class SerializedKeyMap<TKey, TValue> implements Disposable {
   }
 
   dispose = async (): Promise<void> => {
-    this._map.clear();
     this._onDidChange.dispose();
+
+    const promises = [...this._map.values()];
+    this._map.clear();
+
+    const disposing = promises.map(async maybePromise => {
+      // If value is a Promise, it has to be resolved before it can be disposed.
+      const resolved = await maybePromise;
+      if (isDisposable(resolved)) {
+        await resolved.dispose();
+      }
+    });
+
+    await Promise.all(disposing);
   };
 
   get(key: TKey): TValue | undefined {
diff --git a/src/services/ServerManager.ts b/src/services/ServerManager.ts
index 53d4f6dd..a87ebc9b 100644
--- a/src/services/ServerManager.ts
+++ b/src/services/ServerManager.ts
@@ -100,14 +100,21 @@ export class ServerManager implements IServerManager {
 
   canStartServer: boolean;
 
-  async dispose(): Promise<void> {
+  dispose = async (): Promise<void> => {
     this._onDidConnect.dispose();
     this._onDidDisconnect.dispose();
     this._onDidLoadConfig.dispose();
     this._onDidServerStatusChange.dispose();
     this._onDidRegisterEditor.dispose();
     this._onDidUpdate.dispose();
-  }
+
+    await Promise.all([
+      this._connectionMap.dispose(),
+      this._serverMap.dispose(),
+      this._uriConnectionsMap.dispose(),
+      this._workerURLToServerURLMap.dispose(),
+    ]);
+  };
 
   loadServerConfig = async (): Promise<void> => {
     // We want to keep any existing managed servers that aren't overridden by
@@ -243,6 +250,7 @@ export class ServerManager implements IServerManager {
     this._onDidUpdate.fire();
 
     if (!(await connection.initSession())) {
+      connection.dispose();
       this._connectionMap.delete(serverUrl);
       return null;
     }
diff --git a/src/services/cache/ByURLAsyncCache.ts b/src/services/cache/ByURLAsyncCache.ts
index 64f10c92..8f230a54 100644
--- a/src/services/cache/ByURLAsyncCache.ts
+++ b/src/services/cache/ByURLAsyncCache.ts
@@ -1,6 +1,5 @@
 import * as vscode from 'vscode';
 import type { IAsyncCacheService } from '../../types';
-import { isDisposable } from '../../util';
 import { URLMap } from '../URLMap';
 
 /**
@@ -37,18 +36,6 @@ export class ByURLAsyncCache<TValue>
 
   dispose = async (): Promise<void> => {
     this._onDidInvalidate.dispose();
-
-    const promises = [...this._promiseMap.values()];
-    this._promiseMap.clear();
-
-    // Values have to be resolved before they can be disposed.
-    const disposing = promises.map(async promise => {
-      const resolved = await promise;
-      if (isDisposable(resolved)) {
-        await resolved.dispose();
-      }
-    });
-
-    await Promise.all(disposing);
+    await this._promiseMap.dispose();
   };
 }