diff --git a/pyproject.toml b/pyproject.toml
index cdf5e09..66d1994 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -59,7 +59,7 @@ write_to = "src/embcompare/_version.py"
 gui = [
     "streamlit>=1.12,<2",
     "pandas>=1.3,<3.0",
-    "altair>=4.0,<5.0",
+    "altair>=4.0,<6.0",
     "loguru>=0.6,<1.0",
 ]
 dev = [