diff --git a/tools/challenge-md-parser/tests-to-data.js b/tools/challenge-md-parser/tests-to-data.js
index 06c8388efc..bd957a4bcd 100644
--- a/tools/challenge-md-parser/tests-to-data.js
+++ b/tools/challenge-md-parser/tests-to-data.js
@@ -34,7 +34,9 @@ function plugin() {
           );
           tests.question.text = mdToHTML(tests.question.text);
         }
-        if (tests.tests) {
+        // since tests are overloaded (they're both a list of projects and
+        // actual tests), it's necessary to check which they are:
+        if (tests.tests && tests.tests[0] && tests.tests[0].text) {
           tests.tests = tests.tests.map(({ text, testString }) => ({
             text: mdToHTML(text),
             testString