diff --git a/CHANGELOG.md b/CHANGELOG.md
index 0e83c38..4a255e3 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,7 @@
 - Fix file listing when using additional flags [#9](https://github.com/observingClouds/ecmwfspec/issues/9)
 - Fix incorrect caching if cache directory is given as absolute path [#10](https://github.com/observingClouds/ecmwfspec/issues/10)
 - Fix some warnings in test suite. [#11](https://github.com/observingClouds/ecmwfspec/issues/11)
+- Fix ec_cache for `ectmp` file protocol [#12](https://github.com/observingClouds/ecmwfspec/issues/12)
 
 ## 0.0.1
 - Initial release
diff --git a/ecmwfspec/core.py b/ecmwfspec/core.py
index 43b238b..58f634a 100644
--- a/ecmwfspec/core.py
+++ b/ecmwfspec/core.py
@@ -419,8 +419,11 @@ def _open(
         cache_options: Optional[Dict[str, Any]] = None,
         **kwargs: Any,
     ) -> ECFile:
-        path = "TMP" / Path(self._strip_protocol(path))
-        local_path = self.ec_cache.joinpath(*path.parts)
+        if isinstance(path, Path):
+            path = "TMP" / Path(self._strip_protocol(path)).relative_to(path.anchor)
+        elif isinstance(path, str):
+            path = Path("TMP/" + path)
+        local_path = Path(os.path.join(self.ec_cache, path.relative_to(path.anchor)))
         return ECFile(
             str(path),
             str(local_path),
diff --git a/ecmwfspec/tests/conftest.py b/ecmwfspec/tests/conftest.py
index f45a950..17b4e4b 100644
--- a/ecmwfspec/tests/conftest.py
+++ b/ecmwfspec/tests/conftest.py
@@ -114,6 +114,24 @@ def ec_retrieve(self, search_id: int, out_dir: str, preserve_path: bool) -> None
                 shutil.copy(inp_file, Path(out_dir) / inp_file.name)
 
 
+class ECTMPMock(ECMock):
+    """A mock that emulates what ecfs is doing for temporary directories."""
+
+    def __init__(self, _cache: dict[int, builtins.list[str]] = {}) -> None:
+        super().__init__(_cache)
+
+    def cp(self, inp_path: str, out_path: str) -> None:
+        """Mock the ecp method."""
+        inp_path = inp_path.replace("ectmp:", "TMP")
+        os.makedirs(os.path.dirname(out_path), exist_ok=True)
+        _ = (
+            run(["cp", inp_path, out_path], stdout=PIPE, stderr=PIPE)
+            .stdout.decode()
+            .split("\n")
+        )
+        return
+
+
 def create_data(variable_name: str, size: int) -> xr.Dataset:
     """Create a xarray dataset."""
     coords: dict[str, np.ndarray] = {}
@@ -153,6 +171,13 @@ def patch_dir() -> Generator[Path, None, None]:
             yield Path(temp_dir)
 
 
+@pytest.fixture(scope="session")
+def patch_ectmp_dir() -> Generator[Path, None, None]:
+    with TemporaryDirectory() as temp_dir:
+        with mock.patch("ecmwfspec.core.ecfs", ECTMPMock()):
+            yield Path(temp_dir)
+
+
 @pytest.fixture(scope="session")
 def save_dir() -> Generator[Path, None, None]:
     """Create a temporary directory."""
diff --git a/ecmwfspec/tests/test_open_dataset.py b/ecmwfspec/tests/test_open_dataset.py
index 6ca4cc0..f0484c8 100644
--- a/ecmwfspec/tests/test_open_dataset.py
+++ b/ecmwfspec/tests/test_open_dataset.py
@@ -16,6 +16,13 @@
 from ecmwfspec import xr_accessor  # noqa: F401
 
 
+def test_protocols() -> None:
+    """Test that fsspec protocols are registered."""
+    protocols = fsspec.available_protocols()
+    assert "ec" in protocols, f"ec not found in {protocols}"
+    assert "ectmp" in protocols, f"ectmp not found in {protocols}"
+
+
 def test_xr_accessor(patch_dir: Path, zarr_file: Path) -> None:
     """Test staging."""
     zarr_file1 = [*zarr_file.rglob("*.zarr")][0]
@@ -137,6 +144,50 @@ def test_ro_mode(patch_dir: Path) -> None:
     assert url.writable() is False
 
 
+def test_ectmp(patch_ectmp_dir: Path) -> None:
+    """Check if ectmp access works."""
+    import fsspec
+
+    with TemporaryDirectory() as temp_dir:
+        inp_file = Path(temp_dir) / "foo.txt"
+        write_file = (patch_ectmp_dir / "TMP").joinpath(*inp_file.parts[1:])
+        write_file.parent.mkdir(exist_ok=True, parents=True)
+        print(write_file)
+        with write_file.open("w") as f_obj:
+            f_obj.write("foo")
+        url = fsspec.open(
+            f"ectmp:///{inp_file}",
+            ec_cache=patch_ectmp_dir,
+            override=False,
+            mode="rt",
+        ).open()
+    assert Path(url.name) == write_file
+    assert url.tell() == 0
+    assert url.read() == "foo"
+
+
+def test_ectmp_strpath(patch_ectmp_dir: Path) -> None:
+    """Check if ectmp access works."""
+    import fsspec
+
+    with TemporaryDirectory() as temp_dir:
+        inp_file = Path(temp_dir) / "foo.txt"
+        write_file = (patch_ectmp_dir / "TMP").joinpath(*inp_file.parts[1:])
+        write_file.parent.mkdir(exist_ok=True, parents=True)
+        print(write_file)
+        with write_file.open("w") as f_obj:
+            f_obj.write("foo")
+        url = fsspec.open(
+            f"ectmp:///{inp_file}",
+            ec_cache=str(patch_ectmp_dir),
+            override=False,
+            mode="rt",
+        ).open()
+    assert Path(url.name) == write_file
+    assert url.tell() == 0
+    assert url.read() == "foo"
+
+
 def test_list_files(patch_dir: Path, netcdf_files: Path) -> None:
     """Test listing the files."""
     import fsspec