diff --git a/test/assets/output/tocompile.js b/test/assets/output/tocompile.js
index 872ef6d..84bc7a7 100644
--- a/test/assets/output/tocompile.js
+++ b/test/assets/output/tocompile.js
@@ -14,4 +14,4 @@ class test2 {
 const run = async () => {
     return 'hi';
 };
-//# sourceMappingURL=data:application/json;base64,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
\ No newline at end of file
+//# sourceMappingURL=data:application/json;base64,eyJ2ZXJzaW9uIjozLCJmaWxlIjoidG9jb21waWxlLmpzIiwic291cmNlUm9vdCI6IiIsInNvdXJjZXMiOlsiLi4vdG9jb21waWxlLnRzIl0sIm5hbWVzIjpbXSwibWFwcGluZ3MiOiJBQUFBLE9BQU8sQ0FBQyxHQUFHLENBQUMsTUFBTSxDQUFDLENBQUM7QUFDcEIsT0FBTyxDQUFDLEdBQUcsQ0FBQyxPQUFPLENBQUMsQ0FBQztBQUVyQixPQUFPLEtBQUssS0FBSyxNQUFNLGtCQUFrQixDQUFDO0FBRTFDLEtBQUssQ0FBQyxLQUFLLEVBQUUsQ0FBQztBQUNkLEtBQUssQ0FBQyxJQUFJLEVBQUUsQ0FBQztBQUViLE9BQU8sRUFBRSxnQkFBZ0IsRUFBRSxNQUFNLGlCQUFpQixDQUFDO0FBQ25ELE9BQU8sQ0FBQyxHQUFHLENBQUMsZ0JBQWdCLENBQUMsQ0FBQztBQUU5QixNQUFNLEtBQUs7SUFFVDtRQURBLFNBQUksR0FBYSxFQUFFLENBQUM7UUFFbEIsT0FBTyxDQUFDLEdBQUcsQ0FBQyxJQUFJLENBQUMsQ0FBQztJQUNwQixDQUFDO0NBQ0Y7QUFFRCxNQUFNLEdBQUcsR0FBRyxLQUFLLElBQXFCLEVBQUU7SUFDdEMsT0FBTyxJQUFJLENBQUM7QUFDZCxDQUFDLENBQUMifQ==
\ No newline at end of file
diff --git a/test/assets/output/tocompile2.d.ts b/test/assets/output/tocompile2.d.ts
index 2e587e0..b01ef63 100644
--- a/test/assets/output/tocompile2.d.ts
+++ b/test/assets/output/tocompile2.d.ts
@@ -1 +1 @@
-export declare const anExportedString = 'exported string';
+export declare const anExportedString = "exported string";
diff --git a/ts/tsbuild.classes.compiler.ts b/ts/tsbuild.classes.compiler.ts
index 5a0ecc3..4bc43a7 100644
--- a/ts/tsbuild.classes.compiler.ts
+++ b/ts/tsbuild.classes.compiler.ts
@@ -18,6 +18,7 @@ export const compilerOptionsDefault: CompilerOptions = {
   lib: ['lib.dom.d.ts'],
   noImplicitAny: true,
   esModuleInterop: true,
+  useDefineForClassFields: false,
   importsNotUsedAsValues: plugins.typescript.ImportsNotUsedAsValues.Preserve,
 };