diff --git a/test/support/ci/build.sh b/test/support/ci/build.sh
index e743f6db..30250ce0 100755
--- a/test/support/ci/build.sh
+++ b/test/support/ci/build.sh
@@ -15,23 +15,23 @@ elif [[ "$RUBY_PLATFORM" = "java" ]]; then
   echo "
 deb http://deb.debian.org/debian sid main contrib non-free
 deb-src http://deb.debian.org/debian sid main contrib non-free" >> /etc/apt/sources.list
-  apt-get update && apt-get install -y iptables openssl libssl-dev ca-certificates file idn2
+  apt-get update && apt-get install -y build-essential iptables iproute2 openssl libssl-dev ca-certificates file idn2
   update-ca-certificates
 elif [[ ${RUBY_VERSION:0:3} = "2.1" ]]; then
-  apt-get update && apt-get install -y libsodium-dev iptables
+  apt-get update && apt-get install -y libsodium-dev iptables iproute2
   IPTABLES=iptables
 elif [[ ${RUBY_VERSION:0:3} = "2.2" ]]; then
-  apt-get update && apt-get install -y iptables
+  apt-get update && apt-get install -y iptables iproute2
   IPTABLES=iptables
 elif [[ ${RUBY_VERSION:0:3} = "2.3" ]]; then
   # installing custom openssl
-  apt-get update && apt-get install -y iptables iptables-nftables-compat # openssl=1.0.2l openssl-dev=1.0.2l
+  apt-get update && apt-get install -y iptables iproute2 iptables-nftables-compat # openssl=1.0.2l openssl-dev=1.0.2l
   wget http://deb.debian.org/debian/pool/main/o/openssl1.0/libssl1.0.2_1.0.2u-1~deb9u1_amd64.deb
   dpkg -i libssl1.0.2_1.0.2u-1~deb9u1_amd64.deb
   wget http://deb.debian.org/debian/pool/main/o/openssl1.0/libssl1.0-dev_1.0.2u-1~deb9u1_amd64.deb
   dpkg -i libssl1.0-dev_1.0.2u-1~deb9u1_amd64.deb
 else
-  apt-get update && apt-get install -y iptables idn2
+  apt-get update && apt-get install -y iptables iproute2 idn2
 fi
 
 # use port 9090 to test connection timeouts