diff --git a/src/compile/build.ts b/src/compile/build.ts
index db6aee741..a973b964c 100644
--- a/src/compile/build.ts
+++ b/src/compile/build.ts
@@ -95,7 +95,7 @@ async function build(skipSelection: boolean = false, rootFile: string | undefine
     const externalBuildCommand = configuration.get('latex.external.build.command') as string
     const externalBuildArgs = configuration.get('latex.external.build.args') as string[]
 
-    if (rootFile === undefined && lw.file.hasTexLangId(activeEditor.document.languageId)) {
+    if (rootFile === undefined && lw.file.hasTeXLangId(activeEditor.document.languageId)) {
         await lw.root.find()
         rootFile = lw.root.file.path
         languageId = lw.root.file.langId
diff --git a/src/compile/queue.ts b/src/compile/queue.ts
index be8071260..c028dd01f 100644
--- a/src/compile/queue.ts
+++ b/src/compile/queue.ts
@@ -75,7 +75,7 @@ function clear() {
  * @param {Step} step - The Step to check.
  * @returns {boolean} - True if the step is the last one; otherwise, false.
  */
-function isLastStep(step: Step) {
+function isLastStep(step: Step): boolean {
     return stepQueue.steps.length === 0 || stepQueue.steps[0].timestamp !== step.timestamp
 }
 
diff --git a/src/compile/recipe.ts b/src/compile/recipe.ts
index f60bcb338..8160a63e9 100644
--- a/src/compile/recipe.ts
+++ b/src/compile/recipe.ts
@@ -330,8 +330,11 @@ function populateTools(rootFile: string, buildTools: Tool[]): Tool[] {
             }
         }
         tool.args = tool.args?.map(replaceArgumentPlaceholders(rootFile, lw.file.tmpDirPath))
-        tool.outdir = tool.args?.filter(arg => arg.startsWith('-out-directory') || arg.startsWith('-outdir'))[0]?.replace(/^-out-directory=|^-outdir=/, '')
-        tool.auxdir = tool.args?.filter(arg => arg.startsWith('-aux-directory') || arg.startsWith('-auxdir'))[0]?.replace(/^-aux-directory=|^-auxdir=/, '')
+        lw.file.setTeXDirs(
+            rootFile,
+            tool.args?.filter(arg => arg.startsWith('-out-directory') || arg.startsWith('-outdir'))[0]?.replace(/^-out-directory=|^-outdir=/, ''),
+            tool.args?.filter(arg => arg.startsWith('-aux-directory') || arg.startsWith('-auxdir'))[0]?.replace(/^-aux-directory=|^-auxdir=/, '')
+        )
         const env = tool.env ?? {}
         Object.entries(env).forEach(([key, value]) => {
             env[key] = value && replaceArgumentPlaceholders(rootFile, lw.file.tmpDirPath)(value)
diff --git a/src/core/commands.ts b/src/core/commands.ts
index 80986f4d0..82e6231bb 100644
--- a/src/core/commands.ts
+++ b/src/core/commands.ts
@@ -55,7 +55,7 @@ export async function view(mode?: 'tab' | 'browser' | 'external' | vscode.Uri) {
         logger.log('Cannot find active TextEditor.')
         return
     }
-    if (!lw.file.hasTexLangId(vscode.window.activeTextEditor.document.languageId)) {
+    if (!lw.file.hasTeXLangId(vscode.window.activeTextEditor.document.languageId)) {
         logger.log('Active document is not a TeX file.')
         return
     }
@@ -88,7 +88,7 @@ export function kill() {
 
 export function synctex() {
     logger.log('SYNCTEX command invoked.')
-    if (!vscode.window.activeTextEditor || !lw.file.hasTexLangId(vscode.window.activeTextEditor.document.languageId)) {
+    if (!vscode.window.activeTextEditor || !lw.file.hasTeXLangId(vscode.window.activeTextEditor.document.languageId)) {
         logger.log('Cannot start SyncTeX. The active editor is undefined, or the document is not a TeX document.')
         return
     }
@@ -104,7 +104,7 @@ export function synctex() {
 
 export function synctexonref(line: number, filePath: string) {
     logger.log('SYNCTEX command invoked on a reference.')
-    if (!vscode.window.activeTextEditor || !lw.file.hasTexLangId(vscode.window.activeTextEditor.document.languageId)) {
+    if (!vscode.window.activeTextEditor || !lw.file.hasTeXLangId(vscode.window.activeTextEditor.document.languageId)) {
         logger.log('Cannot start SyncTeX. The active editor is undefined, or the document is not a TeX document.')
         return
     }
@@ -132,7 +132,7 @@ export async function clean(): Promise<void> {
 
 export function addTexRoot() {
     logger.log('ADDTEXROOT command invoked.')
-    if (!vscode.window.activeTextEditor || !lw.file.hasTexLangId(vscode.window.activeTextEditor.document.languageId)) {
+    if (!vscode.window.activeTextEditor || !lw.file.hasTeXLangId(vscode.window.activeTextEditor.document.languageId)) {
         return
     }
     lw.extra.texroot()
@@ -145,7 +145,7 @@ export function citation() {
 
 export function wordcount() {
     logger.log('WORDCOUNT command invoked.')
-    if (!vscode.window.activeTextEditor || !lw.file.hasTexLangId(vscode.window.activeTextEditor.document.languageId) ||
+    if (!vscode.window.activeTextEditor || !lw.file.hasTeXLangId(vscode.window.activeTextEditor.document.languageId) ||
         lw.root.file.path === vscode.window.activeTextEditor.document.fileName) {
         if (lw.root.file.path) {
             lw.extra.count(lw.root.file.path, true, true)
@@ -183,7 +183,7 @@ export async function gotoSection(filePath: string, lineNumber: number) {
 
 export function navigateToEnvPair() {
     logger.log('JumpToEnvPair command invoked.')
-    if (!vscode.window.activeTextEditor || !lw.file.hasTexLangId(vscode.window.activeTextEditor.document.languageId)) {
+    if (!vscode.window.activeTextEditor || !lw.file.hasTeXLangId(vscode.window.activeTextEditor.document.languageId)) {
         return
     }
     void lw.locate.pair.goto()
@@ -191,7 +191,7 @@ export function navigateToEnvPair() {
 
 export function selectEnvContent(mode: 'content' | 'whole') {
     logger.log('SelectEnv command invoked.')
-    if (!vscode.window.activeTextEditor || !lw.file.hasTexLangId(vscode.window.activeTextEditor.document.languageId)) {
+    if (!vscode.window.activeTextEditor || !lw.file.hasTeXLangId(vscode.window.activeTextEditor.document.languageId)) {
         return
     }
     void lw.locate.pair.select(mode)
@@ -199,7 +199,7 @@ export function selectEnvContent(mode: 'content' | 'whole') {
 
 export function selectEnvName() {
     logger.log('SelectEnvName command invoked.')
-    if (!vscode.window.activeTextEditor || !lw.file.hasTexLangId(vscode.window.activeTextEditor.document.languageId)) {
+    if (!vscode.window.activeTextEditor || !lw.file.hasTeXLangId(vscode.window.activeTextEditor.document.languageId)) {
         return
     }
     void lw.locate.pair.name('selection')
@@ -207,7 +207,7 @@ export function selectEnvName() {
 
 export function multiCursorEnvName() {
     logger.log('MutliCursorEnvName command invoked.')
-    if (!vscode.window.activeTextEditor || !lw.file.hasTexLangId(vscode.window.activeTextEditor.document.languageId)) {
+    if (!vscode.window.activeTextEditor || !lw.file.hasTeXLangId(vscode.window.activeTextEditor.document.languageId)) {
         return
     }
     void lw.locate.pair.name('cursor')
@@ -215,7 +215,7 @@ export function multiCursorEnvName() {
 
 export function toggleEquationEnv() {
     logger.log('toggleEquationEnv command invoked.')
-    if (!vscode.window.activeTextEditor || !lw.file.hasTexLangId(vscode.window.activeTextEditor.document.languageId)) {
+    if (!vscode.window.activeTextEditor || !lw.file.hasTeXLangId(vscode.window.activeTextEditor.document.languageId)) {
         return
     }
     void lw.locate.pair.name('equationToggle')
@@ -223,7 +223,7 @@ export function toggleEquationEnv() {
 
 export function closeEnv() {
     logger.log('CloseEnv command invoked.')
-    if (!vscode.window.activeTextEditor || !lw.file.hasTexLangId(vscode.window.activeTextEditor.document.languageId)) {
+    if (!vscode.window.activeTextEditor || !lw.file.hasTeXLangId(vscode.window.activeTextEditor.document.languageId)) {
         return
     }
     void lw.locate.pair.close()
diff --git a/src/core/file.ts b/src/core/file.ts
index f2fe7ea6a..a3881c7a7 100644
--- a/src/core/file.ts
+++ b/src/core/file.ts
@@ -19,9 +19,10 @@ export const file = {
     getFlsPath,
     hasBinaryExt,
     hasTeXExt,
-    hasTexLangId,
+    hasTeXLangId,
     hasBibLangId,
     hasDtxLangId,
+    setTeXDirs,
     exists,
     read,
     kpsewhich,
@@ -97,7 +98,7 @@ function hasBinaryExt(extname: string): boolean {
  * @param {string} langId - The language identifier.
  * @returns {boolean} - Indicates whether the language is supported.
  */
-function hasTexLangId(langId: string): boolean {
+function hasTeXLangId(langId: string): boolean {
     return ['tex', 'latex', 'latex-expl3', 'doctex', 'pweave', 'jlweave', 'rsweave'].includes(langId)
 }
 
@@ -121,6 +122,20 @@ function hasDtxLangId(langId: string): boolean {
     return langId === 'doctex'
 }
 
+const texDirs: {[tex: string]: {out?: string, aux?: string}} = {}
+/**
+ * Set the output and aux-files directory for a root file.
+ * @param tex - The path to a root TeX file.
+ * @param out - The corresponding outdir path.
+ * @param aux - The corresponding auxdir path.
+ */
+function setTeXDirs(tex: string, out?: string, aux?: string) {
+    if (!tex.endsWith('.tex')) {
+        tex += '.tex'
+    }
+    texDirs[tex] = {out, aux}
+}
+
 /**
  * Returns the output directory developed according to the input tex path and
  * 'latex.outDir' config. If `texPath` is `undefined`, the default root file is
@@ -141,7 +156,7 @@ function getOutDir(texPath?: string): string {
     const outDir = configuration.get('latex.outDir') as string
     const out = utils.replaceArgumentPlaceholders(texPath, file.tmpDirPath)(outDir)
     if (outDir === '%DIR%' || outDir === '%DIR_W32%') {
-        return lw.compile.lastSteps.filter(step => step.outdir).slice(-1)[0]?.outdir ?? path.normalize(out).split(path.sep).join('/')
+        return texDirs[texPath]?.out ?? path.normalize(out).split(path.sep).join('/')
     }
     return path.normalize(out).split(path.sep).join('/')
 }
@@ -206,7 +221,7 @@ function getFlsPath(texPath: string): string | undefined {
     if (fs.existsSync(flsFile)) {
         return flsFile
     }
-    flsFile = path.resolve(rootDir, lw.compile.lastSteps.filter(step => step.auxdir).slice(-1)[0]?.auxdir ?? '', fileName)
+    flsFile = path.resolve(rootDir, texDirs[texPath]?.aux ?? '', fileName)
     return fs.existsSync(flsFile) ? flsFile : undefined
 }
 
diff --git a/src/extras/counter.ts b/src/extras/counter.ts
index 36a578296..6fbaf84c2 100644
--- a/src/extras/counter.ts
+++ b/src/extras/counter.ts
@@ -26,7 +26,7 @@ loadConfigs()
 
 lw.onConfigChange(['texcount', 'docker.enabled'], loadConfigs)
 lw.onDispose(vscode.window.onDidChangeActiveTextEditor((e: vscode.TextEditor | undefined) => {
-    if (e && lw.file.hasTexLangId(e.document.languageId)) {
+    if (e && lw.file.hasTeXLangId(e.document.languageId)) {
         loadConfigs(e.document.uri)
     } else {
         state.statusBar.hide()
diff --git a/src/locate/synctex.ts b/src/locate/synctex.ts
index 59dc6fa8c..7135a9876 100644
--- a/src/locate/synctex.ts
+++ b/src/locate/synctex.ts
@@ -200,7 +200,7 @@ function toPDF(args?: {line: number, filePath: string}, forcedViewer: 'auto' | '
 
     if (args === undefined) {
         filePath = vscode.window.activeTextEditor.document.uri.fsPath
-        if (!lw.file.hasTexLangId(vscode.window.activeTextEditor.document.languageId)) {
+        if (!lw.file.hasTeXLangId(vscode.window.activeTextEditor.document.languageId)) {
             logger.log(`${filePath} is not valid LaTeX.`)
             return
         }
diff --git a/src/main.ts b/src/main.ts
index cf484f437..4b27c98b2 100644
--- a/src/main.ts
+++ b/src/main.ts
@@ -70,7 +70,7 @@ export function activate(extensionContext: vscode.ExtensionContext) {
         if (e.uri.scheme !== 'file'){
             return
         }
-        if (lw.file.hasTexLangId(e.languageId) ||
+        if (lw.file.hasTeXLangId(e.languageId) ||
             lw.cache.getIncludedTeX(lw.root.file.path, [], false).includes(e.fileName) ||
             lw.cache.getIncludedBib().includes(e.fileName)) {
             logger.log(`onDidSaveTextDocument triggered: ${e.uri.toString(true)}`)
@@ -91,7 +91,7 @@ export function activate(extensionContext: vscode.ExtensionContext) {
     extensionContext.subscriptions.push(vscode.window.onDidChangeActiveTextEditor(async (e: vscode.TextEditor | undefined) => {
         const configuration = vscode.workspace.getConfiguration('latex-workshop')
 
-        if (vscode.window.visibleTextEditors.filter(editor => lw.file.hasTexLangId(editor.document.languageId)).length > 0) {
+        if (vscode.window.visibleTextEditors.filter(editor => lw.file.hasTeXLangId(editor.document.languageId)).length > 0) {
             logger.showStatus()
             if (configuration.get('view.autoFocus.enabled') && !isLaTeXActive) {
                 void vscode.commands.executeCommand('workbench.view.lw.latex-workshop-activitybar').then(() => vscode.commands.executeCommand('workbench.action.focusActiveEditorGroup'))
@@ -103,7 +103,7 @@ export function activate(extensionContext: vscode.ExtensionContext) {
         if (e && e.document.uri.scheme !== 'file'){
             return
         }
-        if (e && lw.file.hasTexLangId(e.document.languageId) && e.document.fileName !== prevTeXDocumentPath) {
+        if (e && lw.file.hasTeXLangId(e.document.languageId) && e.document.fileName !== prevTeXDocumentPath) {
             prevTeXDocumentPath = e.document.fileName
             await lw.root.find()
             lw.lint.latex.root()
@@ -111,7 +111,7 @@ export function activate(extensionContext: vscode.ExtensionContext) {
             isLaTeXActive = false
         }
         if (e && (
-            lw.file.hasTexLangId(e.document.languageId)
+            lw.file.hasTeXLangId(e.document.languageId)
             || lw.file.hasBibLangId(e.document.languageId)
             || lw.file.hasDtxLangId(e.document.languageId))) {
             void lw.outline.refresh()
@@ -122,7 +122,7 @@ export function activate(extensionContext: vscode.ExtensionContext) {
         if (e.document.uri.scheme !== 'file'){
             return
         }
-        if (!lw.file.hasTexLangId(e.document.languageId) &&
+        if (!lw.file.hasTeXLangId(e.document.languageId) &&
             !lw.file.hasBibLangId(e.document.languageId) &&
             !lw.file.hasDtxLangId(e.document.languageId)) {
             return
@@ -133,7 +133,7 @@ export function activate(extensionContext: vscode.ExtensionContext) {
     }))
 
     extensionContext.subscriptions.push(vscode.window.onDidChangeTextEditorSelection((e: vscode.TextEditorSelectionChangeEvent) => {
-        if (lw.file.hasTexLangId(e.textEditor.document.languageId) ||
+        if (lw.file.hasTeXLangId(e.textEditor.document.languageId) ||
             lw.file.hasBibLangId(e.textEditor.document.languageId) ||
             lw.file.hasDtxLangId(e.textEditor.document.languageId)) {
             return lw.outline.reveal(e)
@@ -145,7 +145,7 @@ export function activate(extensionContext: vscode.ExtensionContext) {
 
     void lw.root.find().then(() => {
         lw.lint.latex.root()
-        if (lw.file.hasTexLangId(vscode.window.activeTextEditor?.document.languageId ?? '')) {
+        if (lw.file.hasTeXLangId(vscode.window.activeTextEditor?.document.languageId ?? '')) {
             prevTeXDocumentPath = vscode.window.activeTextEditor?.document.fileName
         }
     })
diff --git a/src/preview/math-preview-panel.ts b/src/preview/math-preview-panel.ts
index 9188e9cd9..393aadbe4 100644
--- a/src/preview/math-preview-panel.ts
+++ b/src/preview/math-preview-panel.ts
@@ -180,7 +180,7 @@ async function update(ev?: UpdateEvent) {
     }
     const editor = vscode.window.activeTextEditor
     const document = editor?.document
-    if (!editor || !document?.languageId || !lw.file.hasTexLangId(document.languageId)) {
+    if (!editor || !document?.languageId || !lw.file.hasTeXLangId(document.languageId)) {
         clearCache()
         return
     }
diff --git a/src/types.ts b/src/types.ts
index 21603b076..ce1d09008 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -64,9 +64,7 @@ export type Tool = {
     name: string,
     command: string,
     args?: string[],
-    env?: ProcessEnv,
-    outdir?: string,
-    auxdir?: string
+    env?: ProcessEnv
 }
 
 export type Recipe = {