diff --git a/lib/images/macos/tools/soak.sh b/lib/images/macos/tools/soak.sh
index 663e897..14d49e1 100755
--- a/lib/images/macos/tools/soak.sh
+++ b/lib/images/macos/tools/soak.sh
@@ -14,8 +14,8 @@ for i in $(seq 1 "$RUNS"); do
   D="$OUT/run-$i"; rm -rf "$D"; mkdir -p "$D"
   rm -rf "/tmp/vmix-macos/$NAME"
   t0=$(date +%s)
-  if [ "$i" -eq 1 ]; then nix build --no-link -L "$DRV^*" > "$D/build.log" 2>&1; rc=$?
-  else nix build --no-link -L --rebuild "$DRV^*" > "$D/build.log" 2>&1; rc=$?; fi
+  if [ "$i" -eq 1 ]; then nix build --no-link -L --option sandbox relaxed "$DRV^*" > "$D/build.log" 2>&1; rc=$?
+  else nix build --no-link -L --option sandbox relaxed --rebuild "$DRV^*" > "$D/build.log" 2>&1; rc=$?; fi
   t1=$(date +%s)
   cp "/tmp/vmix-macos/$NAME"/driver.log "/tmp/vmix-macos/$NAME"/serial.log "$D/" 2>/dev/null
   cp "/tmp/vmix-macos/$NAME"/*.png "$D/" 2>/dev/null