diff --git a/packages/vue-language-core/src/generators/template.ts b/packages/vue-language-core/src/generators/template.ts
index b0935edb9..50c5fa441 100644
--- a/packages/vue-language-core/src/generators/template.ts
+++ b/packages/vue-language-core/src/generators/template.ts
@@ -975,7 +975,7 @@ export function generate(
 					}
 				}
 				else {
-					tsCodeGen.addText('undefined');
+					tsCodeGen.addText('""');
 				}
 				writePropValueSuffix(isStatic);
 				tsCodeGen.addMapping2({