diff --git a/pennylane_lightning/core/src/simulators/lightning_kokkos/catalyst/LightningKokkosSimulator.cpp b/pennylane_lightning/core/src/simulators/lightning_kokkos/catalyst/LightningKokkosSimulator.cpp
index 03598029ad..f42a392075 100644
--- a/pennylane_lightning/core/src/simulators/lightning_kokkos/catalyst/LightningKokkosSimulator.cpp
+++ b/pennylane_lightning/core/src/simulators/lightning_kokkos/catalyst/LightningKokkosSimulator.cpp
@@ -139,7 +139,7 @@ void LightningKokkosSimulator::PrintState() {
 
 void LightningKokkosSimulator::SetState(DataView<std::complex<double>, 1> &data,
                                         std::vector<QubitIdType> &wires) {
-    size_t expected_wires = static_cast<size_t>(log2(data.size()));
+    std::size_t expected_wires = static_cast<std::size_t>(log2(data.size()));
     RT_ASSERT(expected_wires == wires.size());
     std::vector<Kokkos::complex<double>> data_vector(data.begin(), data.end());
     std::vector<std::size_t> wires_size_t(wires.begin(), wires.end());
diff --git a/pennylane_lightning/core/src/simulators/lightning_kokkos/catalyst/LightningKokkosSimulator.hpp b/pennylane_lightning/core/src/simulators/lightning_kokkos/catalyst/LightningKokkosSimulator.hpp
index 7e0955523c..c20b0ded7b 100644
--- a/pennylane_lightning/core/src/simulators/lightning_kokkos/catalyst/LightningKokkosSimulator.hpp
+++ b/pennylane_lightning/core/src/simulators/lightning_kokkos/catalyst/LightningKokkosSimulator.hpp
@@ -118,13 +118,13 @@ class LightningKokkosSimulator final : public Catalyst::Runtime::QuantumDevice {
     [[nodiscard]] auto GetNumQubits() const -> size_t override;
     void StartTapeRecording() override;
     void StopTapeRecording() override;
-    void SetDeviceShots(size_t shots) override;
+    void SetDeviceShots(std::size_t shots) override;
     void SetDevicePRNG(std::mt19937 *) override;
     void SetState(DataView<std::complex<double>, 1> &,
                   std::vector<QubitIdType> &) override;
     void SetBasisState(DataView<int8_t, 1> &,
                        std::vector<QubitIdType> &) override;
-    [[nodiscard]] auto GetDeviceShots() const -> size_t override;
+    [[nodiscard]] auto GetDeviceShots() const -> std::size_t override;
     void PrintState() override;
     [[nodiscard]] auto Zero() const -> Result override;
     [[nodiscard]] auto One() const -> Result override;