diff --git a/layouts/partials/cover.html b/layouts/partials/cover.html
index 6c7d1ae3..8ba2cd35 100644
--- a/layouts/partials/cover.html
+++ b/layouts/partials/cover.html
@@ -9,7 +9,10 @@
{{- if $addLink }}{{ end -}}
{{- $sizes := (slice "360" "480" "720" "1080" "1500") }}
- {{- $processableFormats := (slice "jpg" "jpeg" "png" "tif" "bmp" "gif") }}
+ {{- $processableFormats := (slice "jpg" "jpeg" "png" "tif" "bmp" "gif") -}}
+ {{- if hugo.IsExtended -}}
+ {{- $processableFormats = $processableFormats | append "webp" -}}
+ {{- end -}}
{{- $prod := (hugo.IsProduction | or (eq .Site.Params.env "production")) }}
{{- if (and (in $processableFormats $cover.MediaType.SubType) ($responsiveImages) (eq $prod true)) }}