diff --git a/packages/plugin-legacy/src/index.ts b/packages/plugin-legacy/src/index.ts
index d7f0bb206547aa..0f8b7a8bdf7487 100644
--- a/packages/plugin-legacy/src/index.ts
+++ b/packages/plugin-legacy/src/index.ts
@@ -325,10 +325,6 @@ function viteLegacyPlugin(options: Options = {}): Plugin[] {
       }
       config = _config
 
-      if (!genLegacy || config.build.ssr) {
-        return
-      }
-
       targets =
         options.targets ||
         browserslistLoadConfig({ path: config.root }) ||
@@ -339,6 +335,10 @@ function viteLegacyPlugin(options: Options = {}): Plugin[] {
       isDebug &&
         console.log(`[@vitejs/plugin-legacy] modernTargets:`, modernTargets)
 
+      if (!genLegacy || config.build.ssr) {
+        return
+      }
+
       const getLegacyOutputFileName = (
         fileNames:
           | string