diff --git a/Dockerfile.linux.amd64 b/Dockerfile.linux.amd64
index fb156f8..4a3c672 100644
--- a/Dockerfile.linux.amd64
+++ b/Dockerfile.linux.amd64
@@ -2,6 +2,7 @@ FROM cr.simoncor.net/siempie/hugo-sws:latest
 
 # build cache date argument trick
 ARG CACHE_DATE=2017-04-29
+RUN echo "$CACHE_DATE"
 
 # clone site and template
 RUN set -e \