diff --git a/pydantic_ai_slim/pydantic_ai/durable_exec/temporal/__init__.py b/pydantic_ai_slim/pydantic_ai/durable_exec/temporal/__init__.py
index 9611565fde..9477815be1 100644
--- a/pydantic_ai_slim/pydantic_ai/durable_exec/temporal/__init__.py
+++ b/pydantic_ai_slim/pydantic_ai/durable_exec/temporal/__init__.py
@@ -67,6 +67,7 @@ def _workflow_runner(runner: WorkflowRunner | None) -> WorkflowRunner:
             'rich',
             'httpx',
             'anyio',
+            'sniffio',
             'httpcore',
             # Used by fastmcp via py-key-value-aio
             'beartype',