diff --git a/tests/io/test_miniseed.py b/tests/io/test_miniseed.py
index 46ce055..9da16d2 100644
--- a/tests/io/test_miniseed.py
+++ b/tests/io/test_miniseed.py
@@ -65,3 +65,17 @@ def test_miniseed():
         assert da.coords["network"].values == "DX"
         assert da.coords["location"].values == "00"
         assert da.coords["channel"].values.tolist() == ["HHZ", "HHN", "HHE"]
+
+        # automatically open multiple files
+        da = xd.open_mfdataarray(f"{dirpath}/*.mseed", dim="station", engine="miniseed")
+        assert da.shape == (10, 3, 100)
+        assert da.dims == ("station", "channel", "time")
+        assert da.coords["station"].values.tolist() == [
+            f"CH{i:03d}" for i in range(1, 11)
+        ]
+        assert da.coords["time"].isinterp()
+        assert da.coords["time"][0].values == np.datetime64("1970-01-01T00:00:00")
+        assert da.coords["time"][-1].values == np.datetime64("1970-01-01T00:00:00.990")
+        assert da.coords["network"].values == "DX"
+        assert da.coords["location"].values == "00"
+        assert da.coords["channel"].values.tolist() == ["HHZ", "HHN", "HHE"]
diff --git a/tests/test_routines.py b/tests/test_routines.py
index a5a5dd1..a7ff99c 100644
--- a/tests/test_routines.py
+++ b/tests/test_routines.py
@@ -161,7 +161,7 @@ def test_incompatible_coords(self):
         assert len(dc) == 2
         assert dc[0].equals(da1)
         assert dc[1].equals(da2)
-    
+
     def test_incompatible_sampling_interval(self):
         da1 = DataArray(
             np.random.rand(10, 5),
@@ -192,4 +192,4 @@ def test_expand_scalar_coordinate(self):
         dc = combine_by_coords([da1, da2], dim="space", squeeze=True)
         assert dc.shape == (2, 10)
         assert dc.dims == ("space", "time")
-        assert dc.coords["space"].values.tolist() == [0, 1]
\ No newline at end of file
+        assert dc.coords["space"].values.tolist() == [0, 1]
diff --git a/xdas/core/routines.py b/xdas/core/routines.py
index a38b49d..1ae05b9 100644
--- a/xdas/core/routines.py
+++ b/xdas/core/routines.py
@@ -293,7 +293,8 @@ def open_mfdataarray(
             "The maximum number of file that can be opened at once is for now limited "
             "to 100 000."
         )
-    with ProcessPoolExecutor() as executor:
+    max_workers = 1 if engine == "miniseed" else None  # TODO: dirty fix
+    with ProcessPoolExecutor(max_workers=max_workers) as executor:
         futures = [
             executor.submit(open_dataarray, path, engine=engine) for path in paths
         ]