diff --git a/pyproject.toml b/pyproject.toml
index e7232c2..e435332 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -79,7 +79,7 @@ dev-pytest = [
   "frequenz-repo-config[extra-lint-examples] == 0.13.8",
   "pytest-mock == 3.15.1",
   "pytest-asyncio == 1.3.0",
-  "async-solipsism == 0.8",
+  "async-solipsism == 0.9",
   "hypothesis == 6.142.5",
   "frequenz-quantities[marshmallow]",
 ]