diff --git a/README.md b/README.md
index a13559a..992bbde 100644
--- a/README.md
+++ b/README.md
@@ -47,8 +47,9 @@ body = CircuitJobCreationPayload.from_dict({
     "shots": 100,
     "input": {
         "gateset": "qis",
+        "qubits": 2,
         "circuit": [
-            {"gate": "h", "targets": [0]},
+            {"gate": "h", "target": 0},
             {"gate": "cnot", "control": 0, "target": 1},
         ],
     },
diff --git a/ionq_core/models/qis_circuit_input.py b/ionq_core/models/qis_circuit_input.py
index d8c1ac2..358b3c5 100644
--- a/ionq_core/models/qis_circuit_input.py
+++ b/ionq_core/models/qis_circuit_input.py
@@ -14,7 +14,6 @@
 
 from ..models.qis_circuit_input_gateset import check_qis_circuit_input_gateset
 from ..models.qis_circuit_input_gateset import QisCircuitInputGateset
-from ..types import UNSET, Unset
 from typing import cast
 
 if TYPE_CHECKING:
@@ -32,14 +31,14 @@
 class QisCircuitInput:
     """ 
         Attributes:
+            qubits (int):
             circuit (list[GateQisGate]):
             gateset (QisCircuitInputGateset):
-            qubits (float | Unset):
      """
 
+    qubits: int
     circuit: list[GateQisGate]
     gateset: QisCircuitInputGateset
-    qubits: float | Unset = UNSET
 
 
 
@@ -47,6 +46,8 @@ class QisCircuitInput:
 
     def to_dict(self) -> dict[str, Any]:
         from ..models.gate_qis_gate import GateQisGate
+        qubits = self.qubits
+
         circuit = []
         for circuit_item_data in self.circuit:
             circuit_item = circuit_item_data.to_dict()
@@ -56,17 +57,14 @@ def to_dict(self) -> dict[str, Any]:
 
         gateset: str = self.gateset
 
-        qubits = self.qubits
-
 
         field_dict: dict[str, Any] = {}
 
         field_dict.update({
+            "qubits": qubits,
             "circuit": circuit,
             "gateset": gateset,
         })
-        if qubits is not UNSET:
-            field_dict["qubits"] = qubits
 
         return field_dict
 
@@ -76,6 +74,8 @@ def to_dict(self) -> dict[str, Any]:
     def from_dict(cls: type[T], src_dict: Mapping[str, Any]) -> T:
         from ..models.gate_qis_gate import GateQisGate
         d = dict(src_dict)
+        qubits = d.pop("qubits")
+
         circuit = []
         _circuit = d.pop("circuit")
         for circuit_item_data in (_circuit):
@@ -91,12 +91,10 @@ def from_dict(cls: type[T], src_dict: Mapping[str, Any]) -> T:
 
 
 
-        qubits = d.pop("qubits", UNSET)
-
         qis_circuit_input = cls(
+            qubits=qubits,
             circuit=circuit,
             gateset=gateset,
-            qubits=qubits,
         )
 
         return qis_circuit_input
diff --git a/openapi-overlay.yaml b/openapi-overlay.yaml
new file mode 100644
index 0000000..00c0976
--- /dev/null
+++ b/openapi-overlay.yaml
@@ -0,0 +1,23 @@
+overlay: 1.0.0
+info:
+  title: ionq-core-python local OpenAPI fixes
+  version: 0.1.0
+  description: |
+    Patches applied to openapi.json before client generation. The upstream
+    spec marks QisCircuitInput.qubits as optional and floating-point, but
+    the simulator preflight rejects payloads without it (surfacing as
+    UnexpectedCompilationError) and qubit counts are non-negative integers.
+
+actions:
+  - target: $.components.schemas.QisCircuitInput.required
+    remove: true
+  - target: $.components.schemas.QisCircuitInput
+    update:
+      required:
+        - circuit
+        - gateset
+        - qubits
+  - target: $.components.schemas.QisCircuitInput.properties.qubits
+    update:
+      type: integer
+      format: int32
diff --git a/tests/integration/test_simulator_job.py b/tests/integration/test_simulator_job.py
index fb748ca..602535d 100644
--- a/tests/integration/test_simulator_job.py
+++ b/tests/integration/test_simulator_job.py
@@ -25,8 +25,9 @@
     "shots": 100,
     "input": {
         "gateset": "qis",
+        "qubits": 2,
         "circuit": [
-            {"gate": "h", "targets": [0]},
+            {"gate": "h", "target": 0},
             {"gate": "cnot", "control": 0, "target": 1},
         ],
     },
diff --git a/tests/test_api.py b/tests/test_api.py
index 1a665e9..176829a 100644
--- a/tests/test_api.py
+++ b/tests/test_api.py
@@ -112,7 +112,7 @@ def test_sync(self, httpx_mock, auth_client):
                 "type": "ionq.circuit.v1",
                 "backend": "simulator",
                 "shots": 100,
-                "input": {"gateset": "qis", "circuit": [{"gate": "h", "targets": [0]}]},
+                "input": {"gateset": "qis", "qubits": 1, "circuit": [{"gate": "h", "target": 0}]},
             }
         )
         result = create_job.sync(client=auth_client, body=body)