diff --git a/jest.config.ts b/jest.config.ts
index 7293e5b3be..3203fb2025 100644
--- a/jest.config.ts
+++ b/jest.config.ts
@@ -53,7 +53,7 @@ if (env["GITHUB_ACTIONS"] !== undefined) {
 
     // if we're running against the develop branch, also enable the slow test reporter
     if (env["GITHUB_REF"] == "refs/heads/develop") {
-        reporters.push("<rootDir>/test/slowReporter.js");
+        reporters.push("<rootDir>/test/slowReporter.cjs");
     }
     config.reporters = reporters;
 }
diff --git a/test/slowReporter.js b/test/slowReporter.cjs
similarity index 89%
rename from test/slowReporter.js
rename to test/slowReporter.cjs
index f63f218c36..455b9ba025 100644
--- a/test/slowReporter.js
+++ b/test/slowReporter.cjs
@@ -14,4 +14,4 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-module.exports = require("matrix-js-sdk/spec/slowReporter");
+module.exports = require("matrix-js-sdk/spec/slowReporter.cjs");