diff --git a/packages/squiggle-lang/package.json b/packages/squiggle-lang/package.json
index 92a3b6a282..de52fb36be 100644
--- a/packages/squiggle-lang/package.json
+++ b/packages/squiggle-lang/package.json
@@ -13,7 +13,7 @@
     "build": "pnpm run build:peggy && pnpm run build:ts && pnpm run build:worker",
     "build:peggy": "peggy --cache --format es ./src/ast/peggyParser.peggy",
     "build:ts": "tsc -b",
-    "build:worker": "esbuild src/runners/worker.ts --bundle --minify --platform=browser --outfile=dist/runners/esbuild-worker.cjs",
+    "build:worker": "esbuild src/runners/worker.ts --bundle --minify --platform=browser --format=esm --outfile=dist/runners/esbuild-worker.js",
     "dev": "tsc -b -w",
     "clean": "rm -rf dist && rm -f src/ast/peggyParser.js && rm *.tsbuildinfo",
     "jest": "NODE_OPTIONS=--experimental-vm-modules jest",
diff --git a/packages/squiggle-lang/src/runners/WebWorkerRunner.ts b/packages/squiggle-lang/src/runners/WebWorkerRunner.ts
index e7d15421b3..b51e770f79 100644
--- a/packages/squiggle-lang/src/runners/WebWorkerRunner.ts
+++ b/packages/squiggle-lang/src/runners/WebWorkerRunner.ts
@@ -14,18 +14,11 @@ export class WebWorkerRunner extends AnyWorkerRunner {
      * If you need to touch this code, make sure to check carefully both the components (storybook) and the hub editor.
      * This configuration and the esbuild configuration in `package.json` are extremely fragile.
      *
-     * In particular:
-     * 1. ESM is problematic:`{ type: "module" }` (with `.mjs` or `.js`)will seemingly work, but cause lots of Turbopack CLI errors; Turbopack fails to analyze `(url, { type: "module" })` parameters correctly, as of Next.js 15.0.3.
-     * 2. `.js` extension will collide with the default `"type": "module"` in `package.json`, which will lead to Next.js warnings.
-     *
-     * So, instead, we bundle the worker to the basic IIFE; see `package.json` for details.
-     *
-     * This might cause issues in the future, if we decide to depend on some library that's ESM-only; I'm not sure how good esbuild is for bundling ESM dependencies.
-     *
-     * But, for now, it seems like it's working.
+     * Details here: https://github.com/quantified-uncertainty/squiggle/pull/3456
      */
-    const url = new URL("./esbuild-worker.cjs", import.meta.url);
-    this.worker = new Worker(url);
+    this.worker = new Worker(new URL("./esbuild-worker.js", import.meta.url), {
+      type: "module",
+    });
   }
 
   async getWorker(): Promise<Worker> {
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 1275e5f8e2..b7a9ba2bfa 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -20965,7 +20965,7 @@ snapshots:
       chalk: 4.1.2
       exit: 0.1.2
       graceful-fs: 4.2.11
-      jest-config: 29.7.0(@types/node@22.9.0)(babel-plugin-macros@3.1.0)(ts-node@10.9.2(@types/node@22.9.0)(typescript@5.6.3))
+      jest-config: 29.7.0(@types/node@20.12.7)(babel-plugin-macros@3.1.0)(ts-node@10.9.2(@types/node@20.12.7)(typescript@5.6.3))
       jest-util: 29.7.0
       prompts: 2.4.2
     transitivePeerDependencies:
@@ -21873,7 +21873,7 @@ snapshots:
       eslint: 8.57.0
       eslint-import-resolver-node: 0.3.7
       eslint-import-resolver-typescript: 3.5.3(eslint-plugin-import@2.28.1(eslint@8.57.0))(eslint@8.57.0)
-      eslint-plugin-import: 2.28.1(@typescript-eslint/parser@6.20.0(eslint@8.57.0)(typescript@5.6.3))(eslint-import-resolver-typescript@3.5.3)(eslint@8.57.0)
+      eslint-plugin-import: 2.28.1(@typescript-eslint/parser@6.20.0(eslint@8.57.0)(typescript@5.6.3))(eslint-import-resolver-typescript@3.5.3(eslint-plugin-import@2.28.1(eslint@8.57.0))(eslint@8.57.0))(eslint@8.57.0)
       eslint-plugin-jsx-a11y: 6.7.1(eslint@8.57.0)
       eslint-plugin-react: 7.33.2(eslint@8.57.0)
       eslint-plugin-react-hooks: 4.6.2(eslint@8.57.0)
@@ -21896,7 +21896,7 @@ snapshots:
       debug: 4.3.6
       enhanced-resolve: 5.15.0
       eslint: 8.57.0
-      eslint-plugin-import: 2.28.1(@typescript-eslint/parser@6.20.0(eslint@8.57.0)(typescript@5.6.3))(eslint-import-resolver-typescript@3.5.3)(eslint@8.57.0)
+      eslint-plugin-import: 2.28.1(@typescript-eslint/parser@6.20.0(eslint@8.57.0)(typescript@5.6.3))(eslint-import-resolver-typescript@3.5.3(eslint-plugin-import@2.28.1(eslint@8.57.0))(eslint@8.57.0))(eslint@8.57.0)
       get-tsconfig: 4.7.5
       globby: 13.1.3
       is-core-module: 2.13.1
@@ -21916,7 +21916,7 @@ snapshots:
     transitivePeerDependencies:
       - supports-color
 
-  eslint-plugin-import@2.28.1(@typescript-eslint/parser@6.20.0(eslint@8.57.0)(typescript@5.6.3))(eslint-import-resolver-typescript@3.5.3)(eslint@8.57.0):
+  eslint-plugin-import@2.28.1(@typescript-eslint/parser@6.20.0(eslint@8.57.0)(typescript@5.6.3))(eslint-import-resolver-typescript@3.5.3(eslint-plugin-import@2.28.1(eslint@8.57.0))(eslint@8.57.0))(eslint@8.57.0):
     dependencies:
       array-includes: 3.1.7
       array.prototype.findlastindex: 1.2.3
@@ -23661,7 +23661,7 @@ snapshots:
       create-jest: 29.7.0(babel-plugin-macros@3.1.0)
       exit: 0.1.2
       import-local: 3.1.0
-      jest-config: 29.7.0(@types/node@22.9.0)(babel-plugin-macros@3.1.0)(ts-node@10.9.2(@types/node@22.9.0)(typescript@5.6.3))
+      jest-config: 29.7.0(@types/node@20.12.7)(babel-plugin-macros@3.1.0)(ts-node@10.9.2(@types/node@20.12.7)(typescript@5.6.3))
       jest-util: 29.7.0
       jest-validate: 29.7.0
       yargs: 17.7.2