diff --git a/src/renderer/components/OnboardingModal.tsx b/src/renderer/components/OnboardingModal.tsx
index e46c7ae..6db631c 100644
--- a/src/renderer/components/OnboardingModal.tsx
+++ b/src/renderer/components/OnboardingModal.tsx
@@ -108,9 +108,9 @@ export function OnboardingModal({ open, onClose }: OnboardingModalProps): React.
                 사용할 마이크를 선택하세요. 나중에 설정에서 변경할 수 있습니다.
               </Typography>
               <Stack spacing={1} mb={3}>
-                {devices.map((d) => (
+                {devices.map((d, idx) => (
                   <Box
-                    key={d.deviceId}
+                    key={`${d.deviceId}-${idx}`}
                     onClick={() => {
                       setSelectedDevice(d.deviceId)
                       window.electronAPI.audio.setSelectedDevice({ deviceId: d.deviceId })
diff --git a/src/renderer/components/SettingsModal.tsx b/src/renderer/components/SettingsModal.tsx
index 40f3d96..b63e154 100644
--- a/src/renderer/components/SettingsModal.tsx
+++ b/src/renderer/components/SettingsModal.tsx
@@ -494,8 +494,8 @@ export function SettingsModal({ open, onClose }: SettingsModalProps): React.Reac
                   }}
                   startAdornment={<MicIcon sx={{ color: d3roPalette.text.inactive, mr: 1, fontSize: 18 }} />}
                 >
-                  {audioDevices.map((device) => (
-                    <MenuItem key={device.deviceId} value={device.deviceId}>
+                  {audioDevices.map((device, idx) => (
+                    <MenuItem key={`${device.deviceId}-${idx}`} value={device.deviceId}>
                       {device.label}{device.isDefault ? ' (기본)' : ''}
                     </MenuItem>
                   ))}