diff --git a/build/alpine/install-packages.sh b/build/alpine/install-packages.sh
index ee80f1be..e5a4795b 100755
--- a/build/alpine/install-packages.sh
+++ b/build/alpine/install-packages.sh
@@ -1,6 +1,7 @@
 #!/bin/sh
 
 set -e
+set -o pipefail
 
 apk add --no-cache -U \
     openssl \
@@ -27,6 +28,6 @@ apk add --no-cache -U \
     libpcap
 
 # Patched knockd
-curl -o /tmp/knock.tar.gz https://github.com/Metalcape/knock/releases/download/0.8.1/knock-0.8.1-alpine-amd64.tar.gz
+curl -fsSL -o /tmp/knock.tar.gz https://github.com/Metalcape/knock/releases/download/0.8.1/knock-0.8.1-alpine-amd64.tar.gz
 tar -xf /tmp/knock.tar.gz -C /usr/local/ && rm /tmp/knock.tar.gz
 ln -s /usr/local/sbin/knockd /usr/sbin/knockd
diff --git a/build/ol/install-packages.sh b/build/ol/install-packages.sh
index 3f43840e..5833b27e 100755
--- a/build/ol/install-packages.sh
+++ b/build/ol/install-packages.sh
@@ -2,7 +2,7 @@
 
 export TARGET
 
-set -e
+set -euo pipefail
 
 microdnf install dnf -y
 
@@ -40,6 +40,6 @@ dnf install -y ImageMagick \
 bash /build/ol/install-gosu.sh
 
 # Patched knockd
-curl -o /tmp/knock.tar.gz https://github.com/Metalcape/knock/releases/download/0.8.1/knock-0.8.1-$TARGET.tar.gz
+curl -fsSL -o /tmp/knock.tar.gz https://github.com/Metalcape/knock/releases/download/0.8.1/knock-0.8.1-$TARGET.tar.gz
 tar -xf /tmp/knock.tar.gz -C /usr/local/ && rm /tmp/knock.tar.gz
 ln -s /usr/local/sbin/knockd /usr/sbin/knockd
diff --git a/build/ubuntu/install-packages.sh b/build/ubuntu/install-packages.sh
index 6f5e7dd0..ee112fca 100755
--- a/build/ubuntu/install-packages.sh
+++ b/build/ubuntu/install-packages.sh
@@ -1,8 +1,8 @@
-#!/bin/sh
+#!/bin/bash
 
 export TARGET
 
-set -e
+set -euo pipefail
 
 apt-get update
 
@@ -31,7 +31,7 @@ apt-get install -y \
 apt-get clean
 
 # Patched knockd
-curl -o /tmp/knock.tar.gz https://github.com/Metalcape/knock/releases/download/0.8.1/knock-0.8.1-$TARGET.tar.gz
+curl -fsSL -o /tmp/knock.tar.gz https://github.com/Metalcape/knock/releases/download/0.8.1/knock-0.8.1-$TARGET.tar.gz
 tar -xf /tmp/knock.tar.gz -C /usr/local/ && rm /tmp/knock.tar.gz
 ln -s /usr/local/sbin/knockd /usr/sbin/knockd
 find /usr/lib -name 'libpcap.so.0.8' -execdir cp '{}' libpcap.so.1 \;