diff --git a/scripts/engines/boa.sh b/scripts/engines/boa.sh
index 5ff5e86..b2dd48c 100755
--- a/scripts/engines/boa.sh
+++ b/scripts/engines/boa.sh
@@ -1,12 +1,15 @@
 #!/bin/sh
 
+# boa requires newer-than-stable rust
+rustup install beta
+
 # clone repo and build (no CI builds)
 git clone https://github.com/boa-dev/boa.git --depth 1
 
 cd boa
 git rev-parse HEAD > ../version.txt
 
-cargo build --release --jobs 4 --bin boa
+cargo build --release --jobs 4 --bin boa || exit $?
 
 cp target/release/boa ../boa_bin
 cd ..
diff --git a/scripts/engines/nashorn.sh b/scripts/engines/nashorn.sh
index 40499d8..ecb5002 100755
--- a/scripts/engines/nashorn.sh
+++ b/scripts/engines/nashorn.sh
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 # install java 13
 # sudo apt install openjdk-13-jre-headless
diff --git a/scripts/test262.sh b/scripts/test262.sh
index 96ef4f0..8f6cfcf 100755
--- a/scripts/test262.sh
+++ b/scripts/test262.sh
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 set -x
 
 if [[ ! -d test262 ]]; then