diff --git a/containers/jug/dev.Dockerfile b/containers/jug/dev.Dockerfile
index 10f1c20d77d864d9fece678bc6900c33c094e37f..3bd26e5f6528ae4900e47724548ee27263cb2e3c 100644
--- a/containers/jug/dev.Dockerfile
+++ b/containers/jug/dev.Dockerfile
@@ -50,7 +50,7 @@ RUN declare -A arch=(                                                   \
       ["linux/arm64"]="aarch64"                                         \
     )                                                                   \
  && arch=${arch[${TARGETPLATFORM}]}                                     \
- && spack config --scope site add "packages:all:require:arch=${arch}"   \
+ && spack config --scope site add "packages:all:require:[arch=${arch}]" \
  && spack config blame packages                                         \
  && spack config --scope site add "config:suppress_gpg_warnings:true"   \
  && spack config --scope site add "config:build_jobs:${jobs}"           \