diff --git a/lib/index.js b/lib/index.js
index 11de89c..b1a9846 100644
--- a/lib/index.js
+++ b/lib/index.js
@@ -7,7 +7,11 @@ const Watcher = require("./Watcher");
 function createPreprocessor(preconfig, config, emitter, logger) {
   const cache = new Map();
   const log = logger.create("preprocessor.rollup");
-  const watcher = new Watcher(emitter);
+
+  let watcher;
+  if (!config.singleRun && config.autoWatch) {
+    watcher = new Watcher(emitter);
+  }
 
   return async function preprocess(original, file, done) {
     const location = path.relative(config.basePath, file.path);
@@ -25,8 +29,10 @@ function createPreprocessor(preconfig, config, emitter, logger) {
       const bundle = await rollup.rollup(options);
       cache.set(file.path, bundle.cache);
 
-      const [entry, ...dependencies] = bundle.watchFiles;
-      watcher.add(entry, dependencies);
+      if (watcher) {
+        const [entry, ...dependencies] = bundle.watchFiles;
+        watcher.add(entry, dependencies);
+      }
 
       log.info("Generating bundle for ./%s", location);
       const { output } = await bundle.generate(options);