diff --git a/packages/core/src/common/externals/BrowserExternals.ts b/packages/core/src/common/externals/BrowserExternals.ts
index f14d0e3ad..bea1dc54e 100644
--- a/packages/core/src/common/externals/BrowserExternals.ts
+++ b/packages/core/src/common/externals/BrowserExternals.ts
@@ -6,13 +6,7 @@ import type {
 	ExternalDownloaderOptions,
 	RemoteUriString,
 } from './downloader.js'
-import type {
-	ExternalEventEmitter,
-	ExternalFileSystem,
-	Externals,
-	FsLocation,
-	FsWatcher,
-} from './index.js'
+import type { ExternalEventEmitter, ExternalFileSystem, Externals, FsLocation } from './index.js'
 
 type Listener = (...args: unknown[]) => unknown
 class BrowserEventEmitter implements ExternalEventEmitter {
diff --git a/packages/core/src/common/externals/index.ts b/packages/core/src/common/externals/index.ts
index 789999b3b..5bdaabb54 100644
--- a/packages/core/src/common/externals/index.ts
+++ b/packages/core/src/common/externals/index.ts
@@ -86,29 +86,3 @@ export interface ExternalFileSystem {
  * A file URI string or a URI object.
  */
 export type FsLocation = string | Uri
-
-/**
- * A file system watcher that reports additions, changes, and deletions of files.
- * Changes to directories should not be reported.
- */
-export interface FsWatcher {
-	get isReady(): boolean
-	get watchedFiles(): Set<string>
-
-	on(eventName: 'ready', listener: () => unknown): this
-	once(eventName: 'ready', listener: () => unknown): this
-
-	on(eventName: 'add', listener: (uri: string) => unknown): this
-	once(eventName: 'add', listener: (uri: string) => unknown): this
-
-	on(eventName: 'change', listener: (uri: string) => unknown): this
-	once(eventName: 'change', listener: (uri: string) => unknown): this
-
-	on(eventName: 'unlink', listener: (uri: string) => unknown): this
-	once(eventName: 'unlink', listener: (uri: string) => unknown): this
-
-	on(eventName: 'error', listener: (error: Error) => unknown): this
-	once(eventName: 'error', listener: (error: Error) => unknown): this
-
-	close(): Promise<void>
-}
diff --git a/packages/core/src/service/FsWatcher.ts b/packages/core/src/service/FsWatcher.ts
new file mode 100644
index 000000000..6b88d8bb2
--- /dev/null
+++ b/packages/core/src/service/FsWatcher.ts
@@ -0,0 +1,25 @@
+/**
+ * A file system watcher that reports additions, changes, and deletions of files.
+ * Changes to directories should not be reported.
+ */
+export interface FsWatcher {
+	get isReady(): boolean
+	get watchedFiles(): Set<string>
+
+	on(eventName: 'ready', listener: () => unknown): this
+	once(eventName: 'ready', listener: () => unknown): this
+
+	on(eventName: 'add', listener: (uri: string) => unknown): this
+	once(eventName: 'add', listener: (uri: string) => unknown): this
+
+	on(eventName: 'change', listener: (uri: string) => unknown): this
+	once(eventName: 'change', listener: (uri: string) => unknown): this
+
+	on(eventName: 'unlink', listener: (uri: string) => unknown): this
+	once(eventName: 'unlink', listener: (uri: string) => unknown): this
+
+	on(eventName: 'error', listener: (error: Error) => unknown): this
+	once(eventName: 'error', listener: (error: Error) => unknown): this
+
+	close(): Promise<void>
+}
diff --git a/packages/core/src/service/Project.ts b/packages/core/src/service/Project.ts
index d766db2dd..458e6f019 100644
--- a/packages/core/src/service/Project.ts
+++ b/packages/core/src/service/Project.ts
@@ -2,7 +2,7 @@ import type { Ignore } from 'ignore'
 import ignore from 'ignore'
 import type { TextDocumentContentChangeEvent } from 'vscode-languageserver-textdocument'
 import { TextDocument } from 'vscode-languageserver-textdocument'
-import type { ExternalEventEmitter, Externals, FsWatcher, IntervalId } from '../common/index.js'
+import type { ExternalEventEmitter, Externals, IntervalId } from '../common/index.js'
 import {
 	bufferToString,
 	Logger,
@@ -34,6 +34,7 @@ import { LinterErrorReporter } from './ErrorReporter.js'
 import { ArchiveUriSupporter, FileService, FileUriSupporter } from './FileService.js'
 import type { RootUriString } from './fileUtil.js'
 import { fileUtil } from './fileUtil.js'
+import type { FsWatcher } from './FsWatcher.js'
 import { MetaRegistry } from './MetaRegistry.js'
 import { ProfilerFactory } from './Profiler.js'
 
diff --git a/packages/core/src/service/index.ts b/packages/core/src/service/index.ts
index 05abf06ae..a2e431b06 100644
--- a/packages/core/src/service/index.ts
+++ b/packages/core/src/service/index.ts
@@ -8,6 +8,7 @@ export * from './Downloader.js'
 export * from './ErrorReporter.js'
 export { FileService, UriProtocolSupporter } from './FileService.js'
 export * from './fileUtil.js'
+export * from './FsWatcher.js'
 export * from './Hover.js'
 export * from './MetaRegistry.js'
 export * from './Profiler.js'