diff --git a/glue/sample/src/sinter/_worker.py b/glue/sample/src/sinter/_worker.py
index 498113ef..6a3eafe0 100644
--- a/glue/sample/src/sinter/_worker.py
+++ b/glue/sample/src/sinter/_worker.py
@@ -66,21 +66,21 @@ def auto_dem(circuit: 'stim.Circuit') -> 'stim.DetectorErrorModel':
             approximate_disjoint_errors=True,
             block_decomposition_from_introducing_remnant_edges=False,
             decompose_errors=True,
-            flatten_loops=False,
+            flatten_loops=True,
             ignore_decomposition_failures=False,
         )
     except ValueError:
         pass
 
     # This might be https://github.com/quantumlib/Stim/issues/393
-    # Try turning on loop flattening.
+    # Try turning off loop flattening.
     try:
         return circuit.detector_error_model(
             allow_gauge_detectors=False,
             approximate_disjoint_errors=True,
             block_decomposition_from_introducing_remnant_edges=False,
             decompose_errors=True,
-            flatten_loops=True,
+            flatten_loops=False,
             ignore_decomposition_failures=False,
         )
     except ValueError:
@@ -94,7 +94,7 @@ def auto_dem(circuit: 'stim.Circuit') -> 'stim.DetectorErrorModel':
             approximate_disjoint_errors=True,
             block_decomposition_from_introducing_remnant_edges=False,
             decompose_errors=False,
-            flatten_loops=False,
+            flatten_loops=True,
             ignore_decomposition_failures=False,
         )
     except ValueError:
@@ -106,7 +106,7 @@ def auto_dem(circuit: 'stim.Circuit') -> 'stim.DetectorErrorModel':
         approximate_disjoint_errors=True,
         block_decomposition_from_introducing_remnant_edges=False,
         decompose_errors=False,
-        flatten_loops=True,
+        flatten_loops=False,
         ignore_decomposition_failures=False,
     )