diff --git a/templates/regression/index.html b/templates/regression/index.html
index 87281b81..3e98f1fb 100644
--- a/templates/regression/index.html
+++ b/templates/regression/index.html
@@ -216,8 +216,8 @@ <h5>Regression tests</h5>
 
         $(document).ready(function(){
             const urlParams = new URLSearchParams(window.location.search);
-            const hash = urlParams.get("category");
-            if(hash === "") hash = "1";
+            let hash = urlParams.get("category");
+            if(!hash || hash === "") hash = "1";
             $("#category").find("option").each(function(idx, elm){
                 if($(elm).val() === hash){
                     $(elm).attr("selected",true);
diff --git a/tests/test_regression/test_controllers.py b/tests/test_regression/test_controllers.py
index 83eb4039..b7edab9f 100644
--- a/tests/test_regression/test_controllers.py
+++ b/tests/test_regression/test_controllers.py
@@ -566,3 +566,12 @@ def test_add_test_output_and_check_double_hashes(self):
                 ).count(),
                 1
             )
+
+    def test_category_description_shown_without_tags(self):
+        """Test that category description is shown when accessing /regression/ with category parameter but no tags."""
+        response = self.app.test_client().get('/regression/?category=1')
+        self.assertEqual(response.status_code, 200)
+        # Check that the category description span is present and not hidden
+        self.assertIn('data-category="1"', str(response.data))
+        # The JavaScript should ensure the description is visible, but we can't test JS execution in unit tests
+        # This test verifies the HTML structure is correct for the fix to work