diff --git a/tests/test_pauli_op.cpp b/tests/test_pauli_op.cpp
index ef8e950..640dc9d 100644
--- a/tests/test_pauli_op.cpp
+++ b/tests/test_pauli_op.cpp
@@ -183,7 +183,7 @@ TEST_CASE("test apply multistate multistring") {
 
 TEST_CASE("test apply multistate multistring identity") {
   // Set up PauliOp
-  std::vector<PauliString> pauli_strings(10, "IIII");
+  std::vector<PauliString> pauli_strings(2, "IIII");
   std::vector<std::complex<double>> coeffs(pauli_strings.size(),
                                            1. / pauli_strings.size());
   PauliOp<double> pauli_op(coeffs, pauli_strings);