diff --git a/src/common/controller-helper.js b/src/common/controller-helper.js
index d00f8c4..1aa570a 100644
--- a/src/common/controller-helper.js
+++ b/src/common/controller-helper.js
@@ -4,7 +4,7 @@
  * @return {{patch: patch, search: search, get: get, create: create, update: update, remove: remove}} the common controller methods
  */
 function getControllerMethods (service) {
-  const { injectSearchMeta } = require('./helper')
+  const { injectSearchMeta, setLastModifiedHeader } = require('./helper')
 
   /**
    * create entity by request data
@@ -39,7 +39,9 @@ function getControllerMethods (service) {
    * @param res the http response
    */
   async function get (req, res) {
-    res.json(await service.get(req.params.id, req.query))
+    const result = await service.get(req.params.id, req.query)
+    setLastModifiedHeader(req, res, result)
+    res.json(result)
   }
 
   /**
@@ -50,6 +52,7 @@ function getControllerMethods (service) {
   async function search (req, res) {
     const result = await service.search(req.query)
     injectSearchMeta(req, res, result)
+    setLastModifiedHeader(req, res, result.result)
     res.send(result.result)
   }
 
diff --git a/src/common/helper.js b/src/common/helper.js
index 0d5cb97..6cf0f1b 100644
--- a/src/common/helper.js
+++ b/src/common/helper.js
@@ -72,6 +72,22 @@ function injectSearchMeta (req, res, result) {
   res.set('Access-Control-Expose-Headers', accessControlExposeHeaders)
 }
 
+/**
+ * Set the Last-Modified response header from result.
+ * @param {Object} req the HTTP request
+ * @param {Object} res the HTTP response
+ * @param {Array|Object} result the operation result
+ */
+function setLastModifiedHeader (req, res, result) {
+  if (!Array.isArray(result)) {
+    res.set('Last-Modified', new Date(_.get(result, 'metadata.updated')))
+    return
+  }
+  if (result.length) {
+    res.set('Last-Modified', new Date(Math.max(...result.map(entity => new Date(_.get(entity, 'metadata.updated'))))))
+  }
+}
+
 /**
  * Removes the audit fields created, createdBy, updatedBy from the given entity or an array of entities
  * and moves the updated to metadata
@@ -117,6 +133,7 @@ async function publishError (topic, payload, action) {
 module.exports = {
   getAuthUser,
   injectSearchMeta,
+  setLastModifiedHeader,
   getControllerMethods,
   omitAuditFields,
   publishError
diff --git a/src/modules/skill/service.js b/src/modules/skill/service.js
index 594d362..2ebdb84 100644
--- a/src/modules/skill/service.js
+++ b/src/modules/skill/service.js
@@ -121,7 +121,7 @@ async function patch (id, entity, auth) {
   }
 
   // check if the skill has conflict or not
-  await dbHelper.makeSureUnique(Skill, entity, uniqueFields)
+  await dbHelper.makeSureUnique(Skill, { ...entity, id }, uniqueFields)
 
   if (entity.metadata) {
     const inputFields = Object.keys(entity.metadata)
@@ -177,7 +177,7 @@ async function fullyUpdate (id, entity, auth) {
   }
 
   // check if the skill has conflict or not
-  await dbHelper.makeSureUnique(Skill, entity, uniqueFields)
+  await dbHelper.makeSureUnique(Skill, { ...entity, id }, uniqueFields)
 
   if (Object.keys(entity.metadata).length) {
     // check permission for adding new metadata fields