diff --git a/qiskit/visualization/circuit/latex.py b/qiskit/visualization/circuit/latex.py
index 66e172b1ef85..ad4b8e070e13 100644
--- a/qiskit/visualization/circuit/latex.py
+++ b/qiskit/visualization/circuit/latex.py
@@ -536,7 +536,7 @@ def _build_measure(self, node, col):
             register = get_bit_register(self._circuit, node.cargs[0])
             if register is not None:
                 wire2 = self._wire_map[register]
-                idx_str = str(node.cargs[0].index)
+                idx_str = str(self._circuit.find_bit(node.cargs[0]).registers[0][1])
             else:
                 wire2 = self._wire_map[node.cargs[0]]