diff --git a/pyproject.toml b/pyproject.toml
index 1324c15dc..816d73fc6 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -45,7 +45,7 @@ dependencies = [
 [project.optional-dependencies]
 tests = [
     "ansys-platform-instancemanagement==1.1.2",
-    "dill==0.3.8",
+    "dill==0.3.9",
     "google-api-python-client==2.147.0",
     "googleapis-common-protos==1.65.0",
     "grpcio==1.60.0",