diff --git a/IPython/core/async_helpers.py b/IPython/core/async_helpers.py
index a5affd0..d334dba 100644
--- a/IPython/core/async_helpers.py
+++ b/IPython/core/async_helpers.py
@@ -60,7 +60,7 @@ def _pseudo_sync_runner(coro):
         return exc.value
     else:
         # TODO: do not raise but return an execution result with the right info.
-        raise RuntimeError(f"{coro.__name__!r} needs a real async loop")
+        raise RuntimeError("{coro_name!r} needs a real async loop".format(coro_name=coro.__name__))
 
 
 def _asyncify(code: str) -> str: