diff --git a/src/extension.ts b/src/extension.ts
index 1da9e6c..61fb408 100644
--- a/src/extension.ts
+++ b/src/extension.ts
@@ -8,7 +8,10 @@ import { WorkspaceTracker } from "./project";
 import { TaskProvider } from "./taskProvider";
 import { configureTelemetry, reporter } from "./telemetry";
 import { configureTerminalLinkProvider } from "./terminalLinkProvider";
-import { configureTestController } from "./testController";
+import {
+  configureTestController,
+  handleWorkspaceFolderRemoved as handleTestControllerWorkspaceFolderRemoved,
+} from "./testController";
 import { testElixir } from "./testElixir";
 
 console.log("ElixirLS: Loading extension");
@@ -78,6 +81,7 @@ export function activate(context: vscode.ExtensionContext): ElixirLS {
     vscode.workspace.onDidChangeWorkspaceFolders(async (event) => {
       for (const folder of event.removed) {
         await languageClientManager.handleWorkspaceFolderRemoved(folder);
+        handleTestControllerWorkspaceFolderRemoved(folder);
       }
       // we might have closed client for some nested workspace folder child
       // reopen all needed
diff --git a/src/testController.ts b/src/testController.ts
index fa5866e..e3332fa 100644
--- a/src/testController.ts
+++ b/src/testController.ts
@@ -10,6 +10,16 @@ import type { LanguageClientManager } from "./languageClientManager";
 import { type WorkspaceTracker, getProjectDir } from "./project";
 import { reporter } from "./telemetry";
 
+const workspaceWatchers = new Map<string, vscode.FileSystemWatcher>();
+
+export function handleWorkspaceFolderRemoved(folder: vscode.WorkspaceFolder) {
+  const watcher = workspaceWatchers.get(folder.uri.toString());
+  if (watcher) {
+    watcher.dispose();
+    workspaceWatchers.delete(folder.uri.toString());
+  }
+}
+
 export function configureTestController(
   context: vscode.ExtensionContext,
   languageClientManager: LanguageClientManager,
@@ -350,6 +360,9 @@ export function configureTestController(
 
     await Promise.all(
       outerMostWorkspaceFolders.map(async (workspaceFolder) => {
+        if (workspaceWatchers.has(workspaceFolder.uri.toString())) {
+          return workspaceWatchers.get(workspaceFolder.uri.toString());
+        }
         const projectDir = getProjectDir(workspaceFolder);
         console.log(
           "ElixirLS: registering watcher in",
@@ -361,6 +374,8 @@ export function configureTestController(
         const pattern = new vscode.RelativePattern(projectDir, "**/*_test.exs");
         const watcher = vscode.workspace.createFileSystemWatcher(pattern);
 
+        workspaceWatchers.set(workspaceFolder.uri.toString(), watcher);
+
         context.subscriptions.push(watcher);
 
         // When files are created, make sure there's a corresponding "file" node in the tree