diff --git a/prepare-env.sh b/prepare-env.sh
index 45901e0..29ea82c 100755
--- a/prepare-env.sh
+++ b/prepare-env.sh
@@ -3,7 +3,7 @@ set -exuo pipefail
 
 apt-get update
 
-PACKAGES=git cmake
+PACKAGES="git cmake"
 case "${TARGET}" in
     aarch64-unknown-linux-gnu|aarch64-unknown-linux-musl)
         apt-get install -y "${PACKAGES}" {cpp,g++,gcc}-aarch64-linux-gnu