diff --git a/src/streamsync/core.py b/src/streamsync/core.py
index 8cac3850d..2c1353915 100644
--- a/src/streamsync/core.py
+++ b/src/streamsync/core.py
@@ -239,7 +239,7 @@ def get_mutations_as_dict(self) -> Dict[str, Any]:
             serialised_value = None
             if isinstance(value, StateProxy):
                 if value.initial_assignment:
-                    serialised_mutations[key] = serialised_value
+                    serialised_mutations[escaped_key] = serialised_value
                 value.initial_assignment = False
                 child_mutations = value.get_mutations_as_dict()
                 if child_mutations is None: