diff --git a/core/classifier-jobs/summary-classification.int.test.js b/core/classifier-jobs/summary-classification.int.test.js
index 4794c66e3..4b13ca347 100644
--- a/core/classifier-jobs/summary-classification.int.test.js
+++ b/core/classifier-jobs/summary-classification.int.test.js
@@ -103,9 +103,33 @@ describe('GET /classifier-jobs/{id}/summary/{value}', () => {
     expect(response.body.unreviewed).toEqual(0)
   })
 
-  test.todo('returns 404 on invalid classifier id')
+  test('returns 404 on invalid classifier id', async () => {
+    await models.ClassifierJobSummary.bulkCreate([
+      { classifierJobId: JOB_1.id, classificationId: CLASSIFICATION_1.id, total: 1, confirmed: 1, rejected: 0, uncertain: 0 },
+      { classifierJobId: JOB_1.id, classificationId: CLASSIFICATION_2.id, total: 1, confirmed: 0, rejected: 1, uncertain: 0 },
+      { classifierJobId: JOB_1.id, classificationId: CLASSIFICATION_3.id, total: 1, confirmed: 0, rejected: 0, uncertain: 1 },
+      { classifierJobId: JOB_1.id, classificationId: CLASSIFICATION_4.id, total: 0, confirmed: 0, rejected: 0, uncertain: 0 },
+      { classifierJobId: JOB_2.id, classificationId: CLASSIFICATION_1.id, total: 1, confirmed: 1, rejected: 0, uncertain: 1 }
+    ])
 
-  test.todo('returns 404 on classification value outside the classifier')
+    const response = await request(app).get(`/1928943/summary/${CLASSIFICATION_2.id}`)
 
-  test.todo('returns 404 on classification value that does not have any value')
+    expect(response.statusCode).toEqual(404)
+    expect(response.body.message).toEqual('Classifier job or classification value in the job cannot be found.')
+  })
+
+  test('returns 404 on classification value outside the classifier', async () => {
+    await models.ClassifierJobSummary.bulkCreate([
+      { classifierJobId: JOB_1.id, classificationId: CLASSIFICATION_1.id, total: 1, confirmed: 1, rejected: 0, uncertain: 0 },
+      { classifierJobId: JOB_1.id, classificationId: CLASSIFICATION_2.id, total: 1, confirmed: 0, rejected: 1, uncertain: 0 },
+      { classifierJobId: JOB_1.id, classificationId: CLASSIFICATION_3.id, total: 1, confirmed: 0, rejected: 0, uncertain: 1 },
+      { classifierJobId: JOB_1.id, classificationId: CLASSIFICATION_4.id, total: 0, confirmed: 0, rejected: 0, uncertain: 0 },
+      { classifierJobId: JOB_2.id, classificationId: CLASSIFICATION_1.id, total: 1, confirmed: 1, rejected: 0, uncertain: 1 }
+    ])
+
+    const response = await request(app).get(`/${JOB_2.id}/summary/${CLASSIFICATION_4.id}`)
+
+    expect(response.statusCode).toEqual(404)
+    expect(response.body.message).toEqual('Classifier job or classification value in the job cannot be found.')
+  })
 })
diff --git a/core/classifier-jobs/summary-classification.js b/core/classifier-jobs/summary-classification.js
index 1751c226b..c52054ccf 100644
--- a/core/classifier-jobs/summary-classification.js
+++ b/core/classifier-jobs/summary-classification.js
@@ -36,6 +36,8 @@ const { getSummary } = require('./bl/summary')
  *         description: Insufficient priviledges
  *       404:
  *         description: Classifier job not found or classification value not found.
+ *       5XX:
+ *         description: Other unrecoverable errors.
  *
  */
 module.exports = async (req, res) => {
@@ -45,7 +47,7 @@ module.exports = async (req, res) => {
   try {
     const result = await getSummary(req.params.id, { classificationValue: req.params.value }, { readableBy })
     if (result.total === 0 || result.results.classificationsSummary.length === 0) {
-      throw EmptyResultError('Classifier job summary with given `value` not found.')
+      throw new EmptyResultError('Classifier job or classification value in the job cannot be found.')
     }
     return res.json(result.results.classificationsSummary[0])
   } catch (e) {