diff --git a/packages/framework-tools/src/buildDefaults.ts b/packages/framework-tools/src/buildDefaults.ts
index 3f6222a14af5..d292442b6d74 100644
--- a/packages/framework-tools/src/buildDefaults.ts
+++ b/packages/framework-tools/src/buildDefaults.ts
@@ -71,7 +71,15 @@ export async function build({
     ...buildOptions,
   })
 
-  await fs.writeJSON(path.join(cwd, metafileName), result.metafile, {
-    spaces: 2,
-  })
+  if (result.metafile) {
+    await fs.writeJSON(path.join(cwd, metafileName), result.metafile, {
+      spaces: 2,
+    })
+  } else {
+    console.warn("No metafile found in esbuild's result.")
+    console.warn(
+      'This is unexpected and probably means something is wrong with the ' +
+        'build.',
+    )
+  }
 }