diff --git a/packages/typescript/lib/node/decorateProgram.ts b/packages/typescript/lib/node/decorateProgram.ts
index fdd5354f..3893b199 100644
--- a/packages/typescript/lib/node/decorateProgram.ts
+++ b/packages/typescript/lib/node/decorateProgram.ts
@@ -1,6 +1,6 @@
 import type { Language } from '@volar/language-core';
 import type * as ts from 'typescript';
-import { notEmpty } from './utils';
+import { getServiceScript, notEmpty } from './utils';
 import { transformDiagnostic } from './transform';
 
 export function decorateProgram(language: Language, program: ts.Program) {
@@ -11,6 +11,7 @@ export function decorateProgram(language: Language, program: ts.Program) {
 	const getSyntacticDiagnostics = program.getSyntacticDiagnostics;
 	const getSemanticDiagnostics = program.getSemanticDiagnostics;
 	const getGlobalDiagnostics = program.getGlobalDiagnostics;
+	const getSourceFileByPath = program.getSourceFileByPath;
 
 	// for tsc --noEmit --watch
 	// @ts-ignore
@@ -46,4 +47,17 @@ export function decorateProgram(language: Language, program: ts.Program) {
 			.map(d => transformDiagnostic(language, d))
 			.filter(notEmpty);
 	};
+
+	// fix https://github.com/vuejs/language-tools/issues/4099
+	program.getSourceFileByPath = path => {
+		const sourceFile = getSourceFileByPath(path);
+		if (sourceFile) {
+			const [serviceScript, sourceScript] = getServiceScript(language, sourceFile.fileName);
+			if (serviceScript) {
+				sourceFile.text = sourceScript.snapshot.getText(0, sourceScript.snapshot.getLength())
+					+ sourceFile.text.substring(sourceScript.snapshot.getLength());
+			}
+		}
+		return sourceFile;
+	};
 }
diff --git a/packages/typescript/lib/node/proxyCreateProgram.ts b/packages/typescript/lib/node/proxyCreateProgram.ts
index 190232c3..b3f72f11 100644
--- a/packages/typescript/lib/node/proxyCreateProgram.ts
+++ b/packages/typescript/lib/node/proxyCreateProgram.ts
@@ -1,7 +1,7 @@
-import type * as ts from 'typescript';
-import { decorateProgram } from './decorateProgram';
 import { LanguagePlugin, createLanguage } from '@volar/language-core';
+import type * as ts from 'typescript';
 import { createResolveModuleName } from '../resolveModuleName';
+import { decorateProgram } from './decorateProgram';
 
 export function proxyCreateProgram(
 	ts: typeof import('typescript'),
diff --git a/packages/typescript/lib/node/transform.ts b/packages/typescript/lib/node/transform.ts
index bbed9f1f..626a451d 100644
--- a/packages/typescript/lib/node/transform.ts
+++ b/packages/typescript/lib/node/transform.ts
@@ -3,7 +3,6 @@ import type * as ts from 'typescript';
 import { getServiceScript, notEmpty } from './utils';
 
 const transformedDiagnostics = new WeakMap<ts.Diagnostic, ts.Diagnostic | undefined>();
-const transformedSourceFiles = new WeakMap<ts.SourceFile, ts.SourceFile>();
 
 export function transformCallHierarchyItem(language: Language, item: ts.CallHierarchyItem, filter: (data: CodeInformation) => boolean): ts.CallHierarchyItem {
 	const span = transformSpan(language, item.file, item.span, filter);
@@ -39,7 +38,6 @@ export function transformDiagnostic<T extends ts.Diagnostic>(language: Language,
 						...diagnostic,
 						start: sourceSpan.start,
 						length: sourceSpan.length,
-						file: transformSourceFile(diagnostic.file, sourceScript.snapshot.getText(0, sourceScript.snapshot.getLength())),
 					});
 				}
 			}
@@ -54,16 +52,6 @@ export function transformDiagnostic<T extends ts.Diagnostic>(language: Language,
 	return transformedDiagnostics.get(diagnostic) as T | undefined;
 }
 
-export function transformSourceFile(sourceFile: ts.SourceFile, sourceText: string): ts.SourceFile {
-	if (!transformedSourceFiles.has(sourceFile)) {
-		transformedSourceFiles.set(sourceFile, {
-			...sourceFile,
-			text: sourceText,
-		});
-	}
-	return transformedSourceFiles.get(sourceFile)!;
-}
-
 export function transformFileTextChanges(language: Language, changes: ts.FileTextChanges, filter: (data: CodeInformation) => boolean): ts.FileTextChanges | undefined {
 	const [_, source] = getServiceScript(language, changes.fileName);
 	if (source) {