diff --git a/contrib/build-base.Dockerfile b/contrib/build-base.Dockerfile
index e36bf9d90..64d0e1856 100644
--- a/contrib/build-base.Dockerfile
+++ b/contrib/build-base.Dockerfile
@@ -2,5 +2,7 @@ FROM ubuntu:20.04
 
 ENV DEBIAN_FRONTEND=noninteractive
 
-RUN apt-get update -qq && apt-get -qq -y --no-install-recommends install gcc git build-essential wget ruby-dev ruby1.9.1 lintian rpm help2man man-db
-RUN command -v fpm >/dev/null || sudo gem install fpm --no-ri --no-rdoc
+RUN apt-get update -qq && apt-get -qq -y --no-install-recommends install ca-certificates curl gcc git build-essential wget ruby-dev lintian rpm help2man man-db
+RUN curl -sL -o /usr/local/share/ca-certificates/GlobalSignRootCA_R3.crt https://raw.githubusercontent.com/rubygems/rubygems/master/lib/rubygems/ssl_certs/rubygems.org/GlobalSignRootCA_R3.pem
+RUN update-ca-certificates
+RUN command -v fpm || gem install fpm