diff --git a/pyproject.toml b/pyproject.toml
index fc714d0e..2598be1e 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "vrplib"
-version = "1.3.0"
+version = "1.4.0"
 description = "Python library for reading and writing VRP instances."
 authors = ["Leon Lan <leon.lanyidong@gmail.com>"]
 license = "MIT"