diff --git a/options/locale/locale_en-US.ini b/options/locale/locale_en-US.ini
index 94d7ab27fb..94389a6355 100644
--- a/options/locale/locale_en-US.ini
+++ b/options/locale/locale_en-US.ini
@@ -1027,6 +1027,7 @@ issues.poster = Poster
 issues.collaborator = Collaborator
 issues.owner = Owner
 issues.re_request_review=Re-request review
+issues.is_stale = There have been changes to this PR since this review
 issues.remove_request_review=Remove review request
 issues.remove_request_review_block=Can't remove review request
 issues.sign_in_require_desc = <a href="%s">Sign in</a> to join this conversation.
diff --git a/templates/repo/issue/view_content/pull.tmpl b/templates/repo/issue/view_content/pull.tmpl
index b9254adeab..2a5198f962 100644
--- a/templates/repo/issue/view_content/pull.tmpl
+++ b/templates/repo/issue/view_content/pull.tmpl
@@ -27,7 +27,7 @@
 						</div>
 						<div class="review-item-right">
 							{{if .Stale}}
-							<span class="type-icon text grey">
+							<span class="ui poping up type-icon text grey" data-content="{{$.i18n.Tr "repo.issues.is_stale"}}">
 								<i class="octicon icon fa-hourglass-end"></i>
 							</span>
 							{{end}}