diff --git a/lib/callosum.mjs b/lib/callosum.mjs
index f4c9fca..cf0d497 100644
--- a/lib/callosum.mjs
+++ b/lib/callosum.mjs
@@ -40,7 +40,7 @@ let [forked, workerCount] = [0, null];
 // @todo: support workers in browser?
 const availableParallelism = async (options) => {
     if (!(workerCount || (workerCount = ~~options?.workerCount))) {
-        const { availableParallelism: paralle, cpus } = await import('node:os');
+        const { availableParallelism: paralle, cpus } = await import('os');
         workerCount = paralle ? paralle() : cpus().length;
     }
     return workerCount;
diff --git a/webpack.config.mjs b/webpack.config.mjs
index c85aa2a..7466ecc 100644
--- a/webpack.config.mjs
+++ b/webpack.config.mjs
@@ -66,6 +66,8 @@ export default {
         { './lib/tape.mjs': '{}' },
         { './lib/vision.mjs': '{}' },
         { './lib/web.mjs': '{}' },
+        { 'cluster': '{}' },
+        { 'os': '{}' },
         // { 'node:buffer': '{}' },
         // { 'node:stream': '{}' },
         // { 'node:fs': '{}' },