diff --git a/packages/taler-harness/build.mjs b/packages/taler-harness/build.mjs
index b02d159e1..3fb411342 100755
--- a/packages/taler-harness/build.mjs
+++ b/packages/taler-harness/build.mjs
@@ -15,31 +15,35 @@
  GNU Taler; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
  */
 
-import esbuild from 'esbuild'
-import path from "path"
-import fs from "fs"
+import esbuild from "esbuild";
+import path from "path";
+import fs from "fs";
 
-const BASE = process.cwd()
+const BASE = process.cwd();
 
-let GIT_ROOT = BASE
-while (!fs.existsSync(path.join(GIT_ROOT, '.git')) && GIT_ROOT !== '/') {
-  GIT_ROOT = path.join(GIT_ROOT, '../')
+let GIT_ROOT = BASE;
+while (!fs.existsSync(path.join(GIT_ROOT, ".git")) && GIT_ROOT !== "/") {
+  GIT_ROOT = path.join(GIT_ROOT, "../");
 }
-if (GIT_ROOT === '/') {
-  console.log("not found")
+if (GIT_ROOT === "/") {
+  console.log("not found");
   process.exit(1);
 }
-const GIT_HASH = GIT_ROOT === '/' ? undefined : git_hash()
+const GIT_HASH = GIT_ROOT === "/" ? undefined : git_hash();
 
-
-let _package = JSON.parse(fs.readFileSync(path.join(BASE, 'package.json')));
+let _package = JSON.parse(fs.readFileSync(path.join(BASE, "package.json")));
 
 function git_hash() {
-  const rev = fs.readFileSync(path.join(GIT_ROOT, '.git', 'HEAD')).toString().trim().split(/.*[: ]/).slice(-1)[0];
-  if (rev.indexOf('/') === -1) {
+  const rev = fs
+    .readFileSync(path.join(GIT_ROOT, ".git", "HEAD"))
+    .toString()
+    .trim()
+    .split(/.*[: ]/)
+    .slice(-1)[0];
+  if (rev.indexOf("/") === -1) {
     return rev;
   } else {
-    return fs.readFileSync(path.join(GIT_ROOT, '.git', rev)).toString().trim();
+    return fs.readFileSync(path.join(GIT_ROOT, ".git", rev)).toString().trim();
   }
 }
 
@@ -49,22 +53,19 @@ export const buildConfig = {
   outfile: "dist/taler-harness-bundled.cjs",
   bundle: true,
   minify: false,
-  target: [
-    'es2020'
-  ],
-  format: 'cjs',
-  platform: 'node',
+  target: ["es2020"],
+  format: "cjs",
+  platform: "node",
   sourcemap: true,
+  inject: ["src/import-meta-url.js"],
   define: {
-    '__VERSION__': `"${_package.version}"`,
-    '__GIT_HASH__': `"${GIT_HASH}"`,
+    __VERSION__: `"${_package.version}"`,
+    __GIT_HASH__: `"${GIT_HASH}"`,
+    ["import.meta.url"]: "import_meta_url",
   },
-}
-
-esbuild
-  .build(buildConfig)
-  .catch((e) => {
-    console.log(e)
-    process.exit(1)
-  });
+};
 
+esbuild.build(buildConfig).catch((e) => {
+  console.log(e);
+  process.exit(1);
+});
diff --git a/packages/taler-harness/src/import-meta-url.js b/packages/taler-harness/src/import-meta-url.js
new file mode 100644
index 000000000..b7def9b07
--- /dev/null
+++ b/packages/taler-harness/src/import-meta-url.js
@@ -0,0 +1,2 @@
+// Helper to make 'import.meta.url' available in esbuild-bundled code as well.
+export const import_meta_url = require('url').pathToFileURL(__filename);