diff --git a/slangpy/tests/device/test_precompiled_module.slang b/slangpy/tests/device/test_precompiled_module.slang
new file mode 100644
index 00000000..da2ae612
--- /dev/null
+++ b/slangpy/tests/device/test_precompiled_module.slang
@@ -0,0 +1,6 @@
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+
+float add_floats(float a, float b)
+{
+    return a + b;
+}
diff --git a/slangpy/tests/device/test_precompiled_modules.py b/slangpy/tests/device/test_precompiled_modules.py
new file mode 100644
index 00000000..eff5be8c
--- /dev/null
+++ b/slangpy/tests/device/test_precompiled_modules.py
@@ -0,0 +1,116 @@
+# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+
+import os
+import pytest
+import subprocess
+import shutil
+from pathlib import Path
+
+import slangpy as spy
+from slangpy.testing import helpers
+from slangpy.core.calldata import SLANG_PATH
+
+
+def is_running_in_ci():
+    """Check if we're running in a CI environment."""
+    ci_indicators = ["CI", "GITHUB_ACTIONS", "GITLAB_CI", "JENKINS_URL", "CIRCLECI"]
+    return any(os.environ.get(indicator) for indicator in ci_indicators)
+
+
+def find_slangc():
+    """Find the slangc compiler binary.
+
+    Returns:
+        Path to slangc if found, None otherwise.
+    """
+    # Look for slangc in the build directory
+    root_dir = Path(__file__).parent.parent.parent.parent
+    build_dirs = [
+        root_dir / "build/pip/_deps/slang-src/bin",
+        root_dir / "build/linux-gcc/_deps/slang-src/bin",
+        root_dir / "build/windows-msvc/_deps/slang-src/bin",
+        root_dir / "build/macos-arm64-clang/_deps/slang-src/bin",
+    ]
+
+    for build_dir in build_dirs:
+        slangc_path = build_dir / "slangc"
+        if slangc_path.exists():
+            return slangc_path
+        slangc_path = build_dir / "slangc.exe"
+        if slangc_path.exists():
+            return slangc_path
+
+    return None
+
+
+def compile_precompiled_module(
+    slangc_path: Path, source_file: Path, output_file: Path, include_paths: list[Path] = None
+) -> None:
+    """Compile a .slang file to a .slang-module precompiled module."""
+    cmd = [
+        str(slangc_path),
+        "-emit-ir",
+        "-o",
+        str(output_file),
+    ]
+
+    if include_paths:
+        for include_path in include_paths:
+            cmd.extend(["-I", str(include_path)])
+
+    cmd.append(str(source_file))
+
+    result = subprocess.run(cmd, capture_output=True, text=True)
+
+    if result.returncode != 0:
+        raise RuntimeError(
+            f"Failed to compile {source_file}: {result.stderr}\nstdout: {result.stdout}"
+        )
+
+
+@pytest.mark.parametrize("device_type", helpers.DEFAULT_DEVICE_TYPES)
+def test_precompiled_module_without_source(device_type: spy.DeviceType, tmpdir: str):
+    """Test that precompiled modules are loaded when source .slang file is not present.
+
+    This definitively verifies that .slang-module files are used by compiling a module
+    to a different name (test_no_source) and loading it without the corresponding .slang file.
+    """
+    # Check if slangc is available
+    slangc = find_slangc()
+    if slangc is None:
+        if is_running_in_ci():
+            raise RuntimeError("slangc compiler not found in CI environment")
+        pytest.skip("slangc compiler not found (skipping outside CI)")
+
+    test_dir = Path(__file__).parent
+    cache_dir = Path(tmpdir)
+
+    source_file = test_dir / "test_precompiled_module.slang"
+    precompiled_file = cache_dir / "test_no_source.slang-module"
+
+    compile_precompiled_module(slangc, source_file, precompiled_file)
+    assert precompiled_file.exists()
+
+    include_paths_list = [cache_dir, SLANG_PATH]
+
+    device = spy.Device(
+        type=device_type,
+        enable_print=True,
+        compiler_options={"include_paths": include_paths_list},
+        label=f"test-precompiled-no-source-{device_type.name}",
+    )
+
+    device.slang_session.load_module("slangpy")
+
+    module = device.load_module("test_no_source")
+    m = spy.Module(module)
+
+    # Verify it works correctly
+    result = m.add_floats(3.0, 4.0)
+    assert abs(result - 7.0) < 1e-5
+
+    device.close()
+
+
+if __name__ == "__main__":
+    pytest.main([__file__, "-v", "-s"])