diff --git a/taskvine/src/bindings/python3/ndcctools/taskvine/dask_dag.py b/taskvine/src/bindings/python3/ndcctools/taskvine/dask_dag.py
index 682aff5085..e9165e441f 100644
--- a/taskvine/src/bindings/python3/ndcctools/taskvine/dask_dag.py
+++ b/taskvine/src/bindings/python3/ndcctools/taskvine/dask_dag.py
@@ -77,7 +77,7 @@ def __init__(self, dsk, low_memory_mode=False):
         self._pending_parents_of = defaultdict(lambda: set())
 
         # key->depth. The shallowest level the key is found
-        self._depth_of = defaultdict(lambda: float("inf"))
+        self._depth_of = defaultdict(lambda: float('inf'))
 
         # target keys that the dag should compute
         self._targets = set()