diff --git a/pyproject.toml b/pyproject.toml
index a04552e..a0af478 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -83,7 +83,7 @@ dev-pytest = [
   "frequenz-repo-config[extra-lint-examples] == 0.13.5",
   "pytest-mock == 3.15.1",
   "pytest-asyncio == 1.2.0",
-  "async-solipsism == 0.8",
+  "async-solipsism == 0.9",
   "hypothesis == 6.151.9",
 ]
 dev = [