diff --git a/layouts/partials/GetBlockClass b/layouts/partials/GetBlockClass
index 56022686f708c0c6fdce11e7ee8aba05d4222460..467f6ff82942693a6be429b0eea88f4b340fde75 100644
--- a/layouts/partials/GetBlockClass
+++ b/layouts/partials/GetBlockClass
@@ -10,6 +10,8 @@
   {{- $class = printf "%s block-%s--%s" $class .template .data.layout -}}
 {{- end -}}
 
-{{- $class = printf "%s %s" $class .html_class -}}
+{{- if .html_class -}}
+  {{- $class = printf "%s %s" $class .html_class -}}
+{{ end }}
 
 {{- return $class -}}
\ No newline at end of file