diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 97f59e0..d83f319 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -9,7 +9,7 @@ jobs:
   lint-and-test:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v7
 
       - name: Install shfmt and bats
         run: |
diff --git a/install.sh b/install.sh
index 708e151..b810729 100755
--- a/install.sh
+++ b/install.sh
@@ -64,7 +64,9 @@ case "${1:-}" in
   *) die "unknown argument: $1 (try --help)" ;;
 esac
 
-[ -f "$SRC/muster" ] && [ -d "$SRC/lib" ] || die "run this from a muster checkout (missing muster/ lib/)"
+if [ ! -f "$SRC/muster" ] || [ ! -d "$SRC/lib" ]; then
+  die "run this from a muster checkout (missing muster/ lib/)"
+fi
 
 say "installing muster"
 say "  from: $SRC"