diff --git a/backend/engines/confucius4/main.py b/backend/engines/confucius4/main.py
index 2b188f9b..3983bf6a 100644
--- a/backend/engines/confucius4/main.py
+++ b/backend/engines/confucius4/main.py
@@ -115,7 +115,9 @@ def _load_model(stdout):
     import torch
     from confuciustts.cli.inference import ConfuciusTTS  # type: ignore[import-not-found]
 
-    device = "cuda" if torch.cuda.is_available() else "cpu"
+    device = torch.accelerator.current_accelerator().type  # 'cuda', 'npu', 'mps', 'xpu', 'cpu'
+    if device == "mps":
+        device = "cpu"  # ConfuciusTTS is untested on MPS; fall back to CPU for safety
     _send(stdout, {"op": "progress", "stage": "loading_model", "percent": 50})
 
     _model = ConfuciusTTS(config_path=_config_path(), device=device)
diff --git a/backend/engines/dots_tts/main.py b/backend/engines/dots_tts/main.py
index 36a490b1..19d055d1 100644
--- a/backend/engines/dots_tts/main.py
+++ b/backend/engines/dots_tts/main.py
@@ -115,7 +115,7 @@ def _load_runtime(stdout):
     from dots_tts.runtime import DotsTtsRuntime  # type: ignore[import-not-found]
 
     repo = os.environ.get("OMNIVOICE_DOTS_TTS_MODEL", _DEFAULT_REPO)
-    default_precision = "bfloat16" if torch.cuda.is_available() else "float32"
+    default_precision = "bfloat16" if torch.accelerator.current_accelerator().type != "cpu" else "float32"
     precision = os.environ.get("OMNIVOICE_DOTS_TTS_PRECISION", default_precision)
     optimize = os.environ.get("OMNIVOICE_DOTS_TTS_OPTIMIZE", "0") == "1"