diff --git a/backend/backends/base.py b/backend/backends/base.py
index 70ec11ef..fa1c90ac 100644
--- a/backend/backends/base.py
+++ b/backend/backends/base.py
@@ -6,6 +6,7 @@ voice prompt combination, and model loading progress tracking.
 """
 
 import logging
+import os
 import platform
 from contextlib import contextmanager
 from pathlib import Path
@@ -77,6 +78,13 @@ def is_model_cached(
         return False
 
 
+# Documented escape hatch (docs/content/docs/overview/gpu-acceleration.mdx):
+# users whose GPU has no compiled kernels in the bundled PyTorch set this to run
+# on CPU instead of crashing at generation time.
+FORCE_CPU_ENV_VAR = "VOICEBOX_FORCE_CPU"
+FORCE_CPU_ENABLED_VALUE = "1"
+
+
 def get_torch_device(
     *,
     allow_xpu: bool = False,
@@ -92,7 +100,16 @@ def get_torch_device(
         allow_directml: Check for DirectML (Windows) support.
         allow_mps: Allow MPS (Apple Silicon). If False, MPS falls back to CPU.
         force_cpu_on_mac: Force CPU on macOS regardless of GPU availability.
+
+    The VOICEBOX_FORCE_CPU override wins over every other candidate, and is
+    resolved before torch is imported so it still works when the installed
+    build is the reason CPU is wanted.
     """
+    # Stripped: on Windows, where this override matters most, it is usually set
+    # through the GUI environment editor.
+    if os.environ.get(FORCE_CPU_ENV_VAR, "").strip() == FORCE_CPU_ENABLED_VALUE:
+        return "cpu"
+
     if force_cpu_on_mac and platform.system() == "Darwin":
         return "cpu"
 
diff --git a/backend/tests/test_force_cpu_env.py b/backend/tests/test_force_cpu_env.py
new file mode 100644
index 00000000..d8cd35a0
--- /dev/null
+++ b/backend/tests/test_force_cpu_env.py
@@ -0,0 +1,80 @@
+"""
+Regression tests for the VOICEBOX_FORCE_CPU environment override.
+
+The docs promise (docs/content/docs/developer/tts-generation.mdx) that
+get_torch_device() layers "VOICEBOX_FORCE_CPU environment override" ahead of
+CUDA/XPU/MPS detection, and gpu-acceleration.mdx tells users to set it to fall
+back to CPU when the bundled PyTorch has no kernels for their GPU.
+
+torch is stubbed through sys.modules so these run without a torch install and
+without any GPU.
+
+Usage:
+    python -m pytest backend/tests/test_force_cpu_env.py -v
+"""
+
+import sys
+
+import pytest
+
+from backend.backends.base import get_torch_device
+
+# The documented public name and value of the override. Pinned here independently
+# of the production constants so a rename of either fails these tests.
+FORCE_CPU_ENV_VAR = "VOICEBOX_FORCE_CPU"
+
+# Sentinel for "the variable is not set at all".
+UNSET = None
+
+
+class _FakeCuda:
+    @staticmethod
+    def is_available() -> bool:
+        return True
+
+
+class _FakeTorch:
+    """Minimal stand-in for a CUDA-enabled torch install."""
+
+    cuda = _FakeCuda
+
+
+@pytest.fixture
+def cuda_available(monkeypatch):
+    """Make torch report a usable CUDA device without installing torch."""
+    monkeypatch.setitem(sys.modules, "torch", _FakeTorch)
+
+
+def _set_override(monkeypatch, value):
+    if value is UNSET:
+        monkeypatch.delenv(FORCE_CPU_ENV_VAR, raising=False)
+    else:
+        monkeypatch.setenv(FORCE_CPU_ENV_VAR, value)
+
+
+@pytest.mark.parametrize("value", ["1", " 1 "])
+def test_force_cpu_wins_over_available_cuda(monkeypatch, cuda_available, value):
+    """The documented value must beat an otherwise usable CUDA device.
+
+    Surrounding whitespace is tolerated: on Windows, where this override
+    matters most, it is typically set through the GUI environment editor."""
+    _set_override(monkeypatch, value)
+
+    assert get_torch_device(allow_xpu=True, allow_directml=True, allow_mps=True) == "cpu"
+
+
+@pytest.mark.parametrize("value", [UNSET, "", "0"])
+def test_without_override_cuda_is_still_selected(monkeypatch, cuda_available, value):
+    """Unset or disabled must not disturb normal device detection."""
+    _set_override(monkeypatch, value)
+
+    assert get_torch_device() == "cuda"
+
+
+def test_force_cpu_does_not_need_torch(monkeypatch):
+    """The override is honoured before torch is imported, so it works on a
+    broken/incompatible torch install — which is the case it exists for."""
+    _set_override(monkeypatch, "1")
+    monkeypatch.setitem(sys.modules, "torch", None)  # makes `import torch` raise
+
+    assert get_torch_device() == "cpu"