diff --git a/layouts/_default/_markup/render-link.html b/layouts/_default/_markup/render-link.html
index a02db86..8e0f347 100644
--- a/layouts/_default/_markup/render-link.html
+++ b/layouts/_default/_markup/render-link.html
@@ -1 +1,9 @@
-<a href="{{ .Destination | safeURL }}"{{ with .Title }} title="{{ . }}"{{ end }}>{{ .Text | safeHTML }}{{ if strings.HasPrefix .Destination "http" }}↗{{ end }}</a>
\ No newline at end of file
+{{- $u := urls.Parse .Destination -}}
+<a href="{{ .Destination | safeURL }}"
+  {{- with .Title }} title="{{ . }}"{{ end -}}
+  {{- if $u.IsAbs }} rel="external"{{ end -}}
+>
+  {{- with .Text | safeHTML }}{{ . }}{{ end -}}
+  {{- if $u.IsAbs }}↗{{ end -}}
+</a>
+{{- /* chomp trailing newline */ -}}
\ No newline at end of file