diff --git a/cpp/base91/CMakeLists.txt b/cpp/base91/CMakeLists.txt
index 9f734e30..137debc5 100644
--- a/cpp/base91/CMakeLists.txt
+++ b/cpp/base91/CMakeLists.txt
@@ -37,6 +37,7 @@ TARGET_LINK_LIBRARIES(base91lib
 )
 
 INSTALL(FILES ${CMAKE_CURRENT_BINARY_DIR}/base91lib.wasm DESTINATION dist COMPONENT runtime)
+INSTALL(FILES ${CMAKE_CURRENT_BINARY_DIR}/base91lib.wasm DESTINATION dist-test COMPONENT runtime)
 
 IF (CMAKE_BUILD_TYPE STREQUAL "Debug")
     INSTALL(FILES ${CMAKE_CURRENT_BINARY_DIR}/base91lib.wasm.map DESTINATION dist COMPONENT runtime)
diff --git a/cpp/expat/expatlib/CMakeLists.txt b/cpp/expat/expatlib/CMakeLists.txt
index 4ce580d4..125b28df 100644
--- a/cpp/expat/expatlib/CMakeLists.txt
+++ b/cpp/expat/expatlib/CMakeLists.txt
@@ -37,6 +37,7 @@ TARGET_LINK_LIBRARIES(expatlib
 )
 
 INSTALL(FILES ${CMAKE_CURRENT_BINARY_DIR}/expatlib.wasm DESTINATION dist COMPONENT runtime)
+INSTALL(FILES ${CMAKE_CURRENT_BINARY_DIR}/expatlib.wasm DESTINATION dist-test COMPONENT runtime)
 
 IF (CMAKE_BUILD_TYPE STREQUAL "Debug")
     INSTALL(FILES ${CMAKE_CURRENT_BINARY_DIR}/expatlib.wasm.map DESTINATION dist COMPONENT runtime)
diff --git a/cpp/graphviz/graphvizlib/CMakeLists.txt b/cpp/graphviz/graphvizlib/CMakeLists.txt
index 9bd22368..352e116e 100644
--- a/cpp/graphviz/graphvizlib/CMakeLists.txt
+++ b/cpp/graphviz/graphvizlib/CMakeLists.txt
@@ -90,6 +90,7 @@ TARGET_LINK_LIBRARIES(graphvizlib PRIVATE
 # )
 
 INSTALL(FILES ${CMAKE_CURRENT_BINARY_DIR}/graphvizlib.wasm DESTINATION dist COMPONENT runtime)
+INSTALL(FILES ${CMAKE_CURRENT_BINARY_DIR}/graphvizlib.wasm DESTINATION dist-test COMPONENT runtime)
 
 IF (CMAKE_BUILD_TYPE STREQUAL "Debug")
     INSTALL(FILES ${CMAKE_CURRENT_BINARY_DIR}/graphvizlib.wasm.map DESTINATION dist COMPONENT runtime)
diff --git a/cpp/zstd/CMakeLists.txt b/cpp/zstd/CMakeLists.txt
index ba80b5b7..b53b8e01 100644
--- a/cpp/zstd/CMakeLists.txt
+++ b/cpp/zstd/CMakeLists.txt
@@ -37,6 +37,7 @@ TARGET_LINK_LIBRARIES(zstdlib
 )
 
 INSTALL(FILES ${CMAKE_CURRENT_BINARY_DIR}/zstdlib.wasm DESTINATION dist COMPONENT runtime)
+INSTALL(FILES ${CMAKE_CURRENT_BINARY_DIR}/zstdlib.wasm DESTINATION dist-test COMPONENT runtime)
 
 IF (CMAKE_BUILD_TYPE STREQUAL "Debug")
     INSTALL(FILES ${CMAKE_CURRENT_BINARY_DIR}/zstdlib.wasm.map DESTINATION dist COMPONENT runtime)
diff --git a/package.json b/package.json
index 7373d34d..e4ce260e 100644
--- a/package.json
+++ b/package.json
@@ -152,4 +152,4 @@
     "url": "https://github.com/hpcc-systems/hpcc-js-wasm/issues"
   },
   "homepage": "https://github.com/hpcc-systems/hpcc-js-wasm#readme"
-}
+}
\ No newline at end of file
diff --git a/rollup.config.mjs b/rollup.config.mjs
index 50a8895e..77b1cb02 100644
--- a/rollup.config.mjs
+++ b/rollup.config.mjs
@@ -50,7 +50,7 @@ const nodeTpl = (input, cjsOutput, esOutput) => ({
             include: ["lib-es6/__tests__/*.js"],
             delimiters: ['', ''],
             values: {
-                "../index": "../index-node"
+                "\"../index\"": "\"../index-node\""
             }
         }),
         nodeResolve({
@@ -99,8 +99,9 @@ export default [
     browserTpl("lib-es6/extract", "dist/extract", "dist/extract.es6"),
 
     browserTpl("lib-es6/__tests__/index", "dist-test/index", "dist-test/index.es6"),
-    nodeTpl("lib-es6/__tests__/index", "dist-test/index.node", "dist-test/index.node.es6"),
-    browserTpl("lib-es6/__tests__/worker", "dist-test/worker", "dist-test/worker.es6"),
+    nodeTpl("lib-es6/__tests__/index-node", "dist-test/index.node", "dist-test/index.node.es6"),
+    browserTpl("lib-es6/__tests__/worker-browser", "dist-test/worker", "dist-test/worker.es6"),
+    nodeTpl("lib-es6/__tests__/worker-node", "dist-test/worker.node", "dist-test/worker.node.es6"),
 
     binTpl("lib-es6/__bin__/dot-wasm", "bin/dot-wasm.mjs"),
     binTpl("lib-es6/__bin__/sfx-wasm", "bin/sfx-wasm.mjs"),
diff --git a/src/__tests__/base91.ts b/src/__tests__/base91.ts
index 7a00d287..6aec5a3d 100644
--- a/src/__tests__/base91.ts
+++ b/src/__tests__/base91.ts
@@ -34,32 +34,4 @@ describe("base91", function () {
         const data2 = zstd.decompress(compressed_data2);
         expect(data).to.deep.equal(data2);
     });
-
-    if (globalThis.window?.Worker) {
-        it("worker", async function () {
-            const data = new Uint8Array(Array.from({ length: 1000 }, (_, i) => i % 256));
-
-            const value = await new Promise(resolve => {
-                const myWorker = new Worker("dist-test/worker.js");
-                myWorker.postMessage(data);
-                myWorker.onmessage = function (e) {
-                    resolve(e.data);
-                };
-            });
-            expect(value).to.deep.equal(data);
-        });
-
-        it("worker-es6", async function () {
-            const data = new Uint8Array(Array.from({ length: 1000 }, (_, i) => i % 256));
-
-            const value = await new Promise(resolve => {
-                const myWorker = new Worker("dist-test/worker.es6.js");
-                myWorker.postMessage(data);
-                myWorker.onmessage = function (e) {
-                    resolve(e.data);
-                };
-            });
-            expect(value).to.deep.equal(data);
-        });
-    }
 });
diff --git a/src/__tests__/browser-tests.ts b/src/__tests__/browser-tests.ts
new file mode 100644
index 00000000..14ba6ee2
--- /dev/null
+++ b/src/__tests__/browser-tests.ts
@@ -0,0 +1,29 @@
+import { expect } from "chai";
+
+describe("worker-browser", function () {
+    it("worker-umd", async function () {
+        const data = new Uint8Array(Array.from({ length: 1000 }, (_, i) => i % 256));
+
+        const value = await new Promise(resolve => {
+            const myWorker = new Worker("dist-test/worker.js");
+            myWorker.postMessage(data);
+            myWorker.onmessage = function (e) {
+                resolve(e.data);
+            };
+        });
+        expect(value).to.deep.equal(data);
+    });
+
+    it("worker-esm", async function () {
+        const data = new Uint8Array(Array.from({ length: 1000 }, (_, i) => i % 256));
+
+        const value = await new Promise(resolve => {
+            const myWorker = new Worker("dist-test/worker.es6.js");
+            myWorker.postMessage(data);
+            myWorker.onmessage = function (e) {
+                resolve(e.data);
+            };
+        });
+        expect(value).to.deep.equal(data);
+    });
+});
diff --git a/src/__tests__/index-common.ts b/src/__tests__/index-common.ts
new file mode 100644
index 00000000..4158f497
--- /dev/null
+++ b/src/__tests__/index-common.ts
@@ -0,0 +1,7 @@
+import { wasmFolder } from "../index";
+wasmFolder("dist");
+
+export * from "./base91";
+export * from "./expat";
+export * from "./graphviz";
+export * from "./zstd";
diff --git a/src/__tests__/index-node.ts b/src/__tests__/index-node.ts
new file mode 100644
index 00000000..e346e00c
--- /dev/null
+++ b/src/__tests__/index-node.ts
@@ -0,0 +1,2 @@
+export * from "./index-common";
+export * from "./node-tests";
\ No newline at end of file
diff --git a/src/__tests__/index.ts b/src/__tests__/index.ts
index 4158f497..c56f1449 100644
--- a/src/__tests__/index.ts
+++ b/src/__tests__/index.ts
@@ -1,7 +1,2 @@
-import { wasmFolder } from "../index";
-wasmFolder("dist");
-
-export * from "./base91";
-export * from "./expat";
-export * from "./graphviz";
-export * from "./zstd";
+export * from "./index-common";
+export * from "./browser-tests";
diff --git a/src/__tests__/node-tests.ts b/src/__tests__/node-tests.ts
new file mode 100644
index 00000000..8f53d669
--- /dev/null
+++ b/src/__tests__/node-tests.ts
@@ -0,0 +1,30 @@
+import { expect } from "chai";
+import { Worker } from "node:worker_threads";
+
+describe("worker-node", function () {
+    it("worker-cjs", async function () {
+        const data = new Uint8Array(Array.from({ length: 1000 }, (_, i) => i % 256));
+
+        const value = await new Promise(resolve => {
+            const myWorker = new Worker("./dist-test/worker.node.js");
+            myWorker.postMessage(data);
+            myWorker.on("message", function (data) {
+                resolve(data);
+            });
+        });
+        expect(value).to.deep.equal(data);
+    });
+
+    it("worker-esm", async function () {
+        const data = new Uint8Array(Array.from({ length: 1000 }, (_, i) => i % 256));
+
+        const value = await new Promise(resolve => {
+            const myWorker = new Worker("./dist-test/worker.node.es6.mjs");
+            myWorker.postMessage(data);
+            myWorker.on("message", function (data) {
+                resolve(data);
+            });
+        });
+        expect(value).to.deep.equal(data);
+    });
+});
diff --git a/src/__tests__/worker.ts b/src/__tests__/worker-browser.ts
similarity index 100%
rename from src/__tests__/worker.ts
rename to src/__tests__/worker-browser.ts
diff --git a/src/__tests__/worker-node.ts b/src/__tests__/worker-node.ts
new file mode 100644
index 00000000..f303d1b6
--- /dev/null
+++ b/src/__tests__/worker-node.ts
@@ -0,0 +1,11 @@
+import { parentPort } from "node:worker_threads";
+import { Base91 } from "../index-node";
+
+parentPort?.on("message", async function (data) {
+    const base91 = await Base91.load();
+    const base91Str = base91.encode(data);
+    const data2 = base91.decode(base91Str);
+    parentPort?.postMessage(data2);
+    process.exit(0);
+});
+