diff --git a/cirq-ionq/cirq_ionq/ionq_native_gates.py b/cirq-ionq/cirq_ionq/ionq_native_gates.py
index 9cfcc95d7a1..6a4d5efb233 100644
--- a/cirq-ionq/cirq_ionq/ionq_native_gates.py
+++ b/cirq-ionq/cirq_ionq/ionq_native_gates.py
@@ -248,7 +248,7 @@ def __pow__(self, power):
             return self
 
         if power == -1:
-            return MSGate(phi0=self.phi0 + 0.5, phi1=self.phi1)
+            return MSGate(phi0=self.phi0 + 0.5, phi1=self.phi1, theta=self.theta)
 
         return NotImplemented
 
diff --git a/cirq-ionq/cirq_ionq/ionq_native_gates_test.py b/cirq-ionq/cirq_ionq/ionq_native_gates_test.py
index 294d5938f69..0eaaefba9f4 100644
--- a/cirq-ionq/cirq_ionq/ionq_native_gates_test.py
+++ b/cirq-ionq/cirq_ionq/ionq_native_gates_test.py
@@ -100,7 +100,10 @@ def test_zz_unitary(phase):
     [
         *[ionq.GPIGate(phi=angle) for angle in PARAMS_FOR_ONE_ANGLE_GATE],
         *[ionq.GPI2Gate(phi=angle) for angle in PARAMS_FOR_ONE_ANGLE_GATE],
-        *[ionq.MSGate(phi0=angles[0], phi1=angles[1]) for angles in PARAMS_FOR_TWO_ANGLE_GATE],
+        *[
+            ionq.MSGate(phi0=angles[0], phi1=angles[1], theta=0.8)
+            for angles in PARAMS_FOR_TWO_ANGLE_GATE
+        ],
         *[ionq.ZZGate(theta=angle) for angle in PARAMS_FOR_ONE_ANGLE_GATE],
     ],
 )