diff --git a/packages/vite/src/node/optimizer/scan.ts b/packages/vite/src/node/optimizer/scan.ts
index 9ba65d23684305..d2a8c3bb929666 100644
--- a/packages/vite/src/node/optimizer/scan.ts
+++ b/packages/vite/src/node/optimizer/scan.ts
@@ -433,8 +433,9 @@ function esbuildScanPlugin(
             })
           )
         }
+        const { loader } = config.optimizeDeps?.esbuildOptions ?? {}
         return {
-          loader: ext as Loader,
+          loader: ((loader && loader[`.${ext}`]) || ext) as Loader,
           contents
         }
       })