diff --git a/ironic_ui/karma.conf.js b/ironic_ui/karma.conf.js
index 2385e65a..a5ad9883 100644
--- a/ironic_ui/karma.conf.js
+++ b/ironic_ui/karma.conf.js
@@ -12,12 +12,24 @@
  * limitations under the License.
  */
 
+var fs = require('fs');
+var path = require('path');
+
 (function () {
   'use strict';
 
   module.exports = function (config) {
     // This tox venv is setup in the post-install npm step
-    var toxPath = '../.tox/py38/lib/python3.8/site-packages/';
+    var toxPath = path.resolve('./.tox/npm');
+    if (!toxPath) {
+      console.error('xStatic libraries not found, please run `tox -e npm`');
+      process.exit(1);
+    }
+    toxPath += '/lib/';
+    toxPath += fs.readdirSync(toxPath).find(function(directory) {
+      return directory.indexOf('python') === 0;
+    });
+    toxPath += '/site-packages/';
 
     config.set({
       preprocessors: {
diff --git a/package.json b/package.json
index a71f99e6..f93a6db5 100644
--- a/package.json
+++ b/package.json
@@ -24,7 +24,7 @@
     "karma-threshold-reporter": "^0.1.15"
   },
   "scripts": {
-    "postinstall": "if [ ! -d .tox ] || [ ! -d .tox/py38 ]; then tox -epy38 --notest; fi",
+    "postinstall": "if [ ! -d .tox/npm ]; then tox -e npm --notest; fi",
     "test": "karma start ironic_ui/karma.conf.js --single-run",
     "lint": "eslint --no-color ironic_ui/static",
     "lintq": "eslint --quiet ironic_ui/static"