diff --git a/packages/webpack/src/index.ts b/packages/webpack/src/index.ts
index f02672450..b3eefdd9e 100644
--- a/packages/webpack/src/index.ts
+++ b/packages/webpack/src/index.ts
@@ -145,7 +145,7 @@ export default function WebpackPlugin<Theme extends object>(
                 return escapeCss(css)
               })
               if (replaced)
-                compilation.assets[file] = new WebpackSources.RawSource(code) as any
+                compilation.assets[file] = new WebpackSources.SourceMapSource(code, file, compilation.assets[file].map() as any) as any
             }
           })
         })