diff --git a/layouts/partials/single/thumbnail.html b/layouts/partials/single/thumbnail.html
index cafa989a..cafbbaa5 100644
--- a/layouts/partials/single/thumbnail.html
+++ b/layouts/partials/single/thumbnail.html
@@ -3,7 +3,7 @@
 {{- with .wrapper }}{{ $wrapper = printf "img-wrap %s" . }}{{ end -}}
 {{ $class := "rounded" }}
 {{ with .class }}{{ $class = . }}{{ end }}
-{{- $ratio := .ratio | default "21x9" -}}
+{{- $ratio := .ratio | default (site.Params.thumbnails.ratio | default "21x9") -}}
 {{- $thumbnail := "" -}}
 {{- $credits := "" -}}
 {{ $figclass := .figclass }}
@@ -39,4 +39,4 @@
 
 {{ if $thumbnail -}}
     {{- partial "assets/image.html" (dict "url" $thumbnail "ratio" $ratio "wrapper" $wrapper "class" $class "title" $page.Params.title "caption" $credits "figclass" $figclass "priority" "high") -}}
-{{ end -}}
\ No newline at end of file
+{{ end -}}