diff --git a/scripts/docker-prep.sh b/scripts/docker-prep.sh
index 139e13a..94e1f26 100755
--- a/scripts/docker-prep.sh
+++ b/scripts/docker-prep.sh
@@ -71,7 +71,7 @@ rewrite_package_json() {
   while IFS='=' read -r pkg_name tarball; do
     [[ -z "$pkg_name" ]] && continue
     # Replace "^0.1.0" (or any semver/file: ref) with "file:../.docker-deps/<tarball>"
-    sed -i '' "s|\"${pkg_name}\": \"[^\"]*\"|\"${pkg_name}\": \"file:${rel_prefix}.docker-deps/${tarball}\"|g" "$tmp"
+    sed -i "s|\"${pkg_name}\": \"[^\"]*\"|\"${pkg_name}\": \"file:${rel_prefix}.docker-deps/${tarball}\"|g" "$tmp"
   done < "$TARBALL_MAP_FILE"
 
   mv "$tmp" "$pkg_file"