diff --git a/templates/repo/issue/view_content/sidebar.tmpl b/templates/repo/issue/view_content/sidebar.tmpl
index 8437ab823418..90afe6b85ebb 100644
--- a/templates/repo/issue/view_content/sidebar.tmpl
+++ b/templates/repo/issue/view_content/sidebar.tmpl
@@ -577,8 +577,8 @@
 
 		<div class="ui divider"></div>
 		<div class="ui equal width compact grid">
-			<div class="row gt-ac">
-				{{$issueReferenceLink := printf "%s#%d" .Issue.Repo.FullName .Issue.Index}}
+			{{$issueReferenceLink := printf "%s#%d" .Issue.Repo.FullName .Issue.Index}}
+			<div class="row gt-ac tooltip" data-content="{{$issueReferenceLink}}">
 				<span class="text column truncate">{{.locale.Tr "repo.issues.reference_link" $issueReferenceLink}}</span>
 				<button class="ui two wide button column gt-p-3" data-clipboard-text="{{$issueReferenceLink}}">{{svg "octicon-copy" 14}}</button>
 			</div>