diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index e6af2d39d..52ad57fed 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -32,7 +32,7 @@ jobs:
 
     - name: Create the conda environment
       shell: bash -l {0}
-      run: mamba install -q python=${{ matrix.python_version }} pip jupyterlab_pygments==0.1.0 pytest-cov pytest-rerunfailures nodejs yarn=1 flake8 ipywidgets matplotlib xeus-cling openssl=1.1.1l "traitlets>=5.0.3,<6"
+      run: mamba install -q python=${{ matrix.python_version }} pip jupyterlab_pygments==0.1.0 pytest-cov pytest-rerunfailures nodejs yarn=1 flake8 ipywidgets matplotlib xeus-cling "traitlets>=5.0.3,<6"
 
     - name: Install dependencies
       shell: bash -l {0}
@@ -82,7 +82,7 @@ jobs:
 
     - name: Create the conda environment
       shell: bash -l {0}
-      run: mamba install -q python=${{ matrix.python_version }} pip jupyterlab_pygments==0.1.0 pytest-cov pytest-rerunfailures nodejs yarn=1 flake8 ipywidgets matplotlib xeus-cling openssl=1.1.1l "traitlets>=5.0.3,<6"
+      run: mamba install -q python=${{ matrix.python_version }} pip jupyterlab_pygments==0.1.0 pytest-cov pytest-rerunfailures nodejs yarn=1 flake8 ipywidgets matplotlib xeus-cling "traitlets>=5.0.3,<6"
 
     - name: Install dependencies
       shell: bash -l {0}
diff --git a/packages/jupyterlab-preview/package.json b/packages/jupyterlab-preview/package.json
index a13617cc5..19635570e 100644
--- a/packages/jupyterlab-preview/package.json
+++ b/packages/jupyterlab-preview/package.json
@@ -72,6 +72,7 @@
   },
   "jupyterlab": {
     "extension": true,
+    "webpackConfig": "webpack.lab.config.js",
     "schemaDir": "schema",
     "outputDir": "../../voila/labextension",
     "discovery": {
diff --git a/packages/jupyterlab-preview/webpack.lab.config.js b/packages/jupyterlab-preview/webpack.lab.config.js
new file mode 100644
index 000000000..e7a395519
--- /dev/null
+++ b/packages/jupyterlab-preview/webpack.lab.config.js
@@ -0,0 +1,6 @@
+const crypto = require('crypto');
+
+// Workaround for loaders using "md4" by default, which is not supported in FIPS-compliant OpenSSL
+const cryptoOrigCreateHash = crypto.createHash;
+crypto.createHash = algorithm =>
+  cryptoOrigCreateHash(algorithm === 'md4' ? 'sha256' : algorithm);
diff --git a/packages/voila/package.json b/packages/voila/package.json
index 2c9ed767d..bedcb4456 100644
--- a/packages/voila/package.json
+++ b/packages/voila/package.json
@@ -45,9 +45,9 @@
   },
   "style": "style/index.css",
   "scripts": {
-    "build": "npm run build:lib && webpack",
+    "build": "jlpm run build:lib && webpack",
     "build:lib": "tsc",
-    "build:prod": "npm run build:lib && webpack --production",
+    "build:prod": "jlpm run build:lib && webpack --production",
     "clean": "jlpm run clean:lib",
     "clean:lib": "rimraf lib tsconfig.tsbuildinfo",
     "test": "echo \"Error: no test specified\" && exit 1",
diff --git a/packages/voila/webpack.config.js b/packages/voila/webpack.config.js
index 374574989..104660320 100644
--- a/packages/voila/webpack.config.js
+++ b/packages/voila/webpack.config.js
@@ -1,5 +1,12 @@
 var path = require('path');
 
+const crypto = require('crypto');
+
+// Workaround for loaders using "md4" by default, which is not supported in FIPS-compliant OpenSSL
+const cryptoOrigCreateHash = crypto.createHash;
+crypto.createHash = algorithm =>
+  cryptoOrigCreateHash(algorithm === 'md4' ? 'sha256' : algorithm);
+
 var rules = [
   { test: /\.css$/, use: ['style-loader', 'css-loader'] },
   // required to load font-awesome
diff --git a/voila/notebook_renderer.py b/voila/notebook_renderer.py
index 4a0848cdf..a2de1ba91 100644
--- a/voila/notebook_renderer.py
+++ b/voila/notebook_renderer.py
@@ -306,7 +306,6 @@ async def _jinja_cell_generator(self, nb, kernel_id):
         await self._cleanup_resources()
 
     async def _cleanup_resources(self):
-        await ensure_async(self.executor.km.cleanup_resources())
         await ensure_async(self.executor.kc.stop_channels())
 
     async def load_notebook(self, path):