diff --git a/src/core/file-system.ts b/src/core/file-system.ts
deleted file mode 100644
index 45053116b..000000000
--- a/src/core/file-system.ts
+++ /dev/null
@@ -1,21 +0,0 @@
-import * as vscode from 'vscode'
-import * as fs from 'fs'
-
-export class LwFileSystem {
-    isLocalUri(uri: vscode.Uri): boolean {
-        return uri.scheme === 'file'
-    }
-
-    isVirtualUri(uri: vscode.Uri): boolean {
-        return !this.isLocalUri(uri)
-    }
-
-    async readFileAsBuffer(fileUri: vscode.Uri): Promise<Buffer> {
-        if (this.isLocalUri(fileUri)) {
-            return fs.promises.readFile(fileUri.fsPath)
-        } else {
-            const resultUint8 = await vscode.workspace.fs.readFile(fileUri)
-            return Buffer.from(resultUint8)
-        }
-    }
-}
diff --git a/src/language/definition.ts b/src/language/definition.ts
index d0c04e31d..273158b00 100644
--- a/src/language/definition.ts
+++ b/src/language/definition.ts
@@ -41,7 +41,7 @@ export class DefinitionProvider implements vscode.DefinitionProvider {
     }
 
     provideDefinition(document: vscode.TextDocument, position: vscode.Position): vscode.Location | undefined {
-        if (lw.lwfs.isVirtualUri(document.uri)) {
+        if (document.uri.scheme !== 'file') {
             return
         }
         const token = tokenizer(document, position)
diff --git a/src/language/symbol-document.ts b/src/language/symbol-document.ts
index cddac5226..c388ff520 100644
--- a/src/language/symbol-document.ts
+++ b/src/language/symbol-document.ts
@@ -1,5 +1,4 @@
 import * as vscode from 'vscode'
-import { lw } from '../lw'
 import { TeXElement, TeXElementType } from '../outline/structurelib/types'
 import { buildBibTeX } from '../outline/structurelib/bibtex'
 import { construct as constructLaTeX } from '../outline/structurelib/latex'
@@ -13,7 +12,7 @@ export class DocSymbolProvider implements vscode.DocumentSymbolProvider {
         } else if (document.languageId === 'doctex') {
             return construct(document).then((sections: TeXElement[]) => this.sectionToSymbols(sections))
         }
-        if (lw.lwfs.isVirtualUri(document.uri)) {
+        if (document.uri.scheme !== 'file') {
             return []
         }
         const sections = await constructLaTeX(document.fileName, false)
diff --git a/src/lw.ts b/src/lw.ts
index a0eaf449a..6807a7404 100644
--- a/src/lw.ts
+++ b/src/lw.ts
@@ -13,7 +13,6 @@ import type { Cleaner } from './extras/cleaner'
 import type { LaTeXCommanderTreeView } from './extras/activity-bar'
 import type { Counter } from './extras/counter'
 import type { Linter } from './lint/latex-linter'
-import type { LwFileSystem } from './core/file-system'
 import type { MathPreviewPanel } from './extras/math-preview-panel'
 import type { Section } from './extras/section'
 import type { dupLabelDetector } from './lint/duplicate-label'
@@ -38,7 +37,6 @@ export const lw = {
     cache: {} as typeof cache,
     root: {} as typeof root,
     compile: {} as typeof compile,
-    lwfs: Object.create(null) as LwFileSystem,
     viewer: {} as typeof viewer,
     server: {} as typeof server,
     locate: {} as typeof locate,
diff --git a/src/main.ts b/src/main.ts
index ce0ade89b..cb943f512 100644
--- a/src/main.ts
+++ b/src/main.ts
@@ -38,7 +38,6 @@ import { LaTeXCommanderTreeView } from './extras/activity-bar'
 import { Counter } from './extras/counter'
 import { dupLabelDetector } from './lint/duplicate-label'
 import { Linter } from './lint/latex-linter'
-import { LwFileSystem } from './core/file-system'
 import { MathPreviewPanel } from './extras/math-preview-panel'
 import { Section } from './extras/section'
 import { SnippetView } from './extras/snippet-view'
@@ -57,7 +56,6 @@ const logger = lw.log('Extension')
 
 function initialize(extensionContext: vscode.ExtensionContext) {
     lw.onDispose(undefined, extensionContext.subscriptions)
-    lw.lwfs = new LwFileSystem()
     lw.completer = new Completer()
     lw.atSuggestionCompleter = new AtSuggestionCompleter()
     lw.linter = new Linter()
@@ -113,7 +111,7 @@ export function activate(extensionContext: vscode.ExtensionContext) {
     }))
 
     extensionContext.subscriptions.push(vscode.workspace.onDidSaveTextDocument( (e: vscode.TextDocument) => {
-        if (lw.lwfs.isVirtualUri(e.uri)){
+        if (e.uri.scheme !== 'file'){
             return
         }
         if (lw.file.hasTexLangId(e.languageId) ||
@@ -141,7 +139,7 @@ export function activate(extensionContext: vscode.ExtensionContext) {
         } else if (vscode.window.activeTextEditor && vscode.window.activeTextEditor.document.languageId.toLowerCase() === 'log') {
             logger.showStatus()
         }
-        if (e && lw.lwfs.isVirtualUri(e.document.uri)){
+        if (e && e.document.uri.scheme !== 'file'){
             return
         }
         if (e && lw.file.hasTexLangId(e.document.languageId) && e.document.fileName !== prevTeXDocumentPath) {
@@ -154,7 +152,7 @@ export function activate(extensionContext: vscode.ExtensionContext) {
     }))
 
     extensionContext.subscriptions.push(vscode.workspace.onDidChangeTextDocument((e: vscode.TextDocumentChangeEvent) => {
-        if (lw.lwfs.isVirtualUri(e.document.uri)){
+        if (e.document.uri.scheme !== 'file'){
             return
         }
         if (!lw.file.hasTexLangId(e.document.languageId) &&
diff --git a/src/preview/server.ts b/src/preview/server.ts
index 2fb69f10f..014dea076 100644
--- a/src/preview/server.ts
+++ b/src/preview/server.ts
@@ -193,7 +193,7 @@ async function handler(request: http.IncomingMessage, response: http.ServerRespo
             return
         }
         try {
-            const buf: Buffer = await lw.lwfs.readFileAsBuffer(fileUri)
+            const buf: Buffer = Buffer.from(await vscode.workspace.fs.readFile(fileUri))
             sendOkResponse(response, buf, 'application/pdf')
             logger.log(`Preview PDF file: ${fileUri.toString(true)}`)
         } catch (e) {