diff --git a/flake8_async/runner.py b/flake8_async/runner.py
index 4562892..38ff3f5 100644
--- a/flake8_async/runner.py
+++ b/flake8_async/runner.py
@@ -138,7 +138,14 @@ def __init__(self, options: Options, module: Module):
 
     def run(self) -> Iterable[Error]:
         for v in (*self.utility_visitors, *self.visitors):
-            self.module = cst.MetadataWrapper(self.module).visit(v)
+            # The default deepcopy guards against the same CST node object
+            # appearing at two positions in the tree (metadata is keyed by node
+            # identity). Parser output and the result of a prior .visit() never
+            # share nodes, so the copy is wasted work. This stays safe as long
+            # as no visitor returns a cached CST node from multiple leave_* calls.
+            self.module = cst.MetadataWrapper(self.module, unsafe_skip_copy=True).visit(
+                v
+            )
 
         yield from self.state.problems