diff --git a/pyproject.toml b/pyproject.toml
index d63503c..f1a3400 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -94,7 +94,7 @@ dev-pytest = [
   "frequenz-repo-config[extra-lint-examples] == 0.17.0",
   "pytest-mock == 3.15.1",
   "pytest-asyncio == 1.3.0",
-  "async-solipsism == 0.8",
+  "async-solipsism == 0.9",
   "time-machine == 3.2.0",
 ]
 dev = [