diff --git a/.changeset/slow-plums-bake.md b/.changeset/slow-plums-bake.md
index e43136d1..d2c64e13 100644
--- a/.changeset/slow-plums-bake.md
+++ b/.changeset/slow-plums-bake.md
@@ -2,4 +2,4 @@
 'playroom': patch
 ---
 
-Restrict VanillaExtract plugin to playroom's source `.css.ts` files only
+Restrict `playroom`'s Vanilla Extract plugin to only process playroom's `.css.ts` files
diff --git a/lib/makeWebpackConfig.js b/lib/makeWebpackConfig.js
index 5856217f..05a5fcd1 100644
--- a/lib/makeWebpackConfig.js
+++ b/lib/makeWebpackConfig.js
@@ -185,7 +185,9 @@ module.exports = async (playroomConfig, options) => {
           // Only apply VanillaExtract plugin to playroom's source `.css.ts` files
           return (
             /\.css\.ts$/i.test(filePath) &&
-            includePaths.some((playRoomPath) => filePath.includes(playRoomPath))
+            includePaths.some((playroomPath) =>
+              filePath.startsWith(playroomPath)
+            )
           );
         },
       }),