diff --git a/ubuntu/20/Dockerfile b/ubuntu/20/Dockerfile
index 8bcd0c8..28fe7a2 100644
--- a/ubuntu/20/Dockerfile
+++ b/ubuntu/20/Dockerfile
@@ -5,7 +5,7 @@ MAINTAINER Gerrit Code Review Community
 RUN apt-get update && \
     apt-get -y install gnupg2
 RUN echo "deb mirror://mirrorlist.gerritforge.com/bionic gerrit contrib" > /etc/apt/sources.list.d/GerritForge.list
-RUN apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 847005AE619067D5
+RUN apt-key adv --keyserver hkp://keyserver.ubuntu.com --recv-keys 847005AE619067D5
 
 RUN apt-get update
 RUN apt-key update