diff --git a/brainglobe_stitch/image_mosaic.py b/brainglobe_stitch/image_mosaic.py
index 75b30fe..1a2a56d 100644
--- a/brainglobe_stitch/image_mosaic.py
+++ b/brainglobe_stitch/image_mosaic.py
@@ -93,6 +93,10 @@ def __init__(self, directory: Path):
             self.tiles[0].resolution_pyramid
         )
 
+    def __del__(self):
+        if self.h5_file is not None:
+            self.h5_file.close()
+
     def load_mesospim_directory(self) -> None:
         """
         Load the mesoSPIM directory and its data into the ImageMosaic.
diff --git a/tests/test_unit/test_image_mosaic.py b/tests/test_unit/test_image_mosaic.py
index fe83f2c..9dc1016 100644
--- a/tests/test_unit/test_image_mosaic.py
+++ b/tests/test_unit/test_image_mosaic.py
@@ -10,7 +10,9 @@ def image_mosaic(naive_bdv_directory):
     os.remove(naive_bdv_directory / "test_data_bdv_tile_config.txt")
     image_mosaic = ImageMosaic(naive_bdv_directory)
 
-    return image_mosaic
+    yield image_mosaic
+
+    del image_mosaic
 
 
 def test_image_mosaic_init(image_mosaic, naive_bdv_directory):
@@ -24,3 +26,16 @@ def test_image_mosaic_init(image_mosaic, naive_bdv_directory):
         image_mosaic.h5_path
         == naive_bdv_directory / "test_data_original_bdv.h5"
     )
+    assert (
+        image_mosaic.meta_path
+        == naive_bdv_directory / "test_data_bdv.h5_meta.txt"
+    )
+    assert image_mosaic.h5_file is not None
+    assert len(image_mosaic.channel_names) == 2
+    assert len(image_mosaic.tiles) == 8
+    assert len(image_mosaic.tile_names) == 8
+    assert image_mosaic.x_y_resolution == 4.08
+    assert image_mosaic.z_resolution == 5.0
+    assert image_mosaic.num_channels == 2
+    assert len(image_mosaic.intensity_adjusted) == 5
+    assert len(image_mosaic.overlaps_interpolated) == 5