diff --git a/modules/entry/back/models/specs/entry-observation.spec.js b/modules/entry/back/models/specs/entry-observation.spec.js
new file mode 100644
index 0000000000..fca13139c4
--- /dev/null
+++ b/modules/entry/back/models/specs/entry-observation.spec.js
@@ -0,0 +1,29 @@
+const app = require('vn-loopback/server/server');
+
+describe('EntryObservation', () => {
+    const entryId = 1;
+
+    it('should throw a user error if the observation type is duplicated.', async() => {
+        const observations = [
+            {
+                entryFk: entryId,
+                observationTypeFk: 1,
+                description: 'repeated description'
+            },
+            {
+                entryFk: entryId,
+                observationTypeFk: 1,
+                description: 'repeated description'
+            },
+        ];
+
+        let error;
+        try {
+            await app.models.EntryObservation.create(observations);
+        } catch (e) {
+            error = e;
+        }
+
+        expect(error).toBeDefined();
+    });
+});