diff --git a/setup.py b/setup.py
index 79a2ada..ea751c9 100644
--- a/setup.py
+++ b/setup.py
@@ -45,7 +45,7 @@ def build_highs():
                 "--depth",
                 "1",
                 "--branch",
-                "v1.8.1",
+                "v1.9.0",
                 "https://github.com/ERGO-Code/HiGHS.git",
             ],
             cwd=this_directory,
@@ -160,7 +160,7 @@ def patch_rpath(executable_path: str):
 
     setup(
         name="highsbox",
-        version="1.8.1",
+        version="1.9.0",
         cmdclass=cmdclass,
         author="Yue Yang",
         author_email="metab0t@outlook.com",