diff --git a/pytket/extensions/cutensornet/structured_state/mps_gate.py b/pytket/extensions/cutensornet/structured_state/mps_gate.py
index 0ca7bed..22b38a8 100644
--- a/pytket/extensions/cutensornet/structured_state/mps_gate.py
+++ b/pytket/extensions/cutensornet/structured_state/mps_gate.py
@@ -234,7 +234,7 @@ def _apply_2q_unitary_nonadjacent(
 
         # Always canonicalise. Even in the case of exact simulation (no truncation)
         # canonicalisation may reduce the bond dimension (thanks to reduced QR).
-        self.canonicalise(l_pos, l_pos)
+        self.canonicalise(l_pos, r_pos)
 
         # Reshape into a rank-4 tensor
         gate_tensor = cp.reshape(unitary, (2, 2, 2, 2))