diff --git a/pyproject.toml b/pyproject.toml
index e632e621..3b7f8678 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -66,7 +66,7 @@ more-itertools = "~=10.4.0"
 pre-commit = "==v3.8.0"
 pytest-xdist = "^3.5.0"
 types-PyYAML = "^6.0.9"
-msgpack-types = "^0.3"
+msgpack-types = "^0.4"
 envclasses = "^0.3.1"
 jedi = "*"
 jaxtyping = "*"