diff --git a/scripts/docker-prep.sh b/scripts/docker-prep.sh
index 3cd4145..d233273 100755
--- a/scripts/docker-prep.sh
+++ b/scripts/docker-prep.sh
@@ -32,9 +32,9 @@ echo "=== docker-prep: packing @bytelyst/* tarballs ==="
 rm -rf "$TARBALL_DIR"
 mkdir -p "$TARBALL_DIR"
 
-# Build all packages first
+# Build all packages first (--filter limits to packages/, skips services/)
 echo "Building @bytelyst/* packages..."
-(cd "$COMMON_PLAT" && pnpm build)
+(cd "$COMMON_PLAT" && pnpm -r --filter './packages/*' build)
 
 # Pack each package and build a mapping of name → tarball filename
 # (uses a temp file instead of associative array for bash 3.2 compat)