diff --git a/checkbox-ng/plainbox/impl/exporter/test_xlsx.py b/checkbox-ng/plainbox/impl/exporter/test_xlsx.py
index a276506825..f1a0c8732a 100644
--- a/checkbox-ng/plainbox/impl/exporter/test_xlsx.py
+++ b/checkbox-ng/plainbox/impl/exporter/test_xlsx.py
@@ -21,6 +21,9 @@
 from unittest.mock import MagicMock, ANY
 
 from plainbox.impl.exporter.xlsx import XLSXSessionStateExporter
+from plainbox.impl.session import SessionState
+from plainbox.impl.unit.job import JobDefinition
+from plainbox.impl.unit.category import CategoryUnit
 
 
 class XLSXSessionStateExporterTests(TestCase):
@@ -52,3 +55,47 @@ def test_write_job(self):
         self_mock.worksheet3.write.assert_any_call(ANY, ANY, "", ANY)
         # self_mock.worksheet3.write.assert_called_with(ANY, ANY, "", ANY)
         # self.assertEqual(self_mock.worksheet3.write.call_count, 2)
+
+    def test_category_map(self):
+        self_mock = MagicMock()
+        A = JobDefinition({"id": "A", "category_id": "test"})
+        B = JobDefinition({"id": "B", "certification-status": "blocker"})
+        job_list = [A, B]
+        unit = MagicMock(name="unit", spec_set=CategoryUnit)
+        unit.id = "test"
+        unit.tr_name.return_value = "Test"
+        unit.Meta.name = "category"
+
+        state = SessionState(job_list)
+        state.update_desired_job_list(job_list)
+        state.unit_list.append(unit)
+
+        self.assertEqual(
+            XLSXSessionStateExporter._category_map(self_mock, state),
+            {"test": "Test"},
+        )
+
+    def test_write_tp_export(self):
+        self_mock = MagicMock()
+        self_mock._category_map.return_value = {
+            "com.canonical.plainbox::uncategorised": "test"
+        }
+        data = MagicMock()
+        A = JobDefinition({"id": "A"})
+        B = JobDefinition({"id": "B", "certification-status": "blocker"})
+        job_list = [A, B]
+        unit = MagicMock(name="unit", spec_set=CategoryUnit)
+        unit.Meta.name = "category"
+
+        state = SessionState(job_list)
+        state.update_desired_job_list(job_list)
+        state.unit_list.append(unit)
+
+        data["manager"].default_device_context.state = state
+        XLSXSessionStateExporter.write_tp_export(self_mock, data)
+        self_mock.worksheet4.write_row.assert_any_call(
+            ANY, 0, ["A", "", "A"], ANY
+        )
+        self_mock.worksheet4.write_row.assert_any_call(
+            ANY, 0, ["B", "blocker", "B"], ANY
+        )
diff --git a/checkbox-ng/plainbox/impl/exporter/xlsx.py b/checkbox-ng/plainbox/impl/exporter/xlsx.py
index e1d9a11b5f..297f0d7362 100644
--- a/checkbox-ng/plainbox/impl/exporter/xlsx.py
+++ b/checkbox-ng/plainbox/impl/exporter/xlsx.py
@@ -877,24 +877,23 @@ def write_results(self, data):
             )
         self.worksheet3.autofilter(5, max_level, self._lineno, max_level + 3)
 
-    def write_tp_export(self, data):
-        def _category_map(state):
-            """Map from category id to their corresponding translated names."""
-            wanted_category_ids = frozenset(
-                {
-                    job_state.effective_category_id
-                    for job_state in state.job_state_map.values()
-                    if job_state.job in state.run_list
-                    and job_state.job.plugin not in ("resource", "attachment")
-                }
-            )
-            return {
-                unit.id: unit.tr_name()
-                for unit in state.unit_list
-                if unit.Meta.name == "category"
-                and unit.id in wanted_category_ids
+    def _category_map(self, state):
+        """Map from category id to their corresponding translated names."""
+        wanted_category_ids = frozenset(
+            {
+                job_state.effective_category_id
+                for job_state in state.job_state_map.values()
+                if job_state.job in state.run_list
+                and job_state.job.plugin not in ("resource", "attachment")
             }
+        )
+        return {
+            unit.id: unit.tr_name()
+            for unit in state.unit_list
+            if unit.Meta.name == "category" and unit.id in wanted_category_ids
+        }
 
+    def write_tp_export(self, data):
         self.worksheet4.set_header(
             "&C{}".format(data["manager"].test_plans[0])
         )
@@ -912,7 +911,7 @@ def _category_map(state):
         self.worksheet4.repeat_rows(0)
         self._lineno = 0
         state = data["manager"].default_device_context.state
-        cat_map = _category_map(state)
+        cat_map = self._category_map(state)
         run_list_ids = [job.id for job in state.run_list]
         for cat_id in sorted(cat_map, key=lambda x: cat_map[x].casefold()):
             self._lineno += 1