diff --git a/dfm_tools/download.py b/dfm_tools/download.py
index 699d9235..979f7476 100644
--- a/dfm_tools/download.py
+++ b/dfm_tools/download.py
@@ -351,8 +351,8 @@ def copernicusmarine_get_buffer(dataset_id):
         resolution = ds.latitude.attrs["step"]
         buffer = 2 * resolution
     except (AttributeError, KeyError, TypeError):
-        print("failed to automatically derive a buffer from the dataset, using buffer=0")
-        buffer = 0
+        print("failed to automatically derive a buffer from the dataset, using buffer=0.5")
+        buffer = 0.5
     return buffer
 
 
diff --git a/tests/test_download.py b/tests/test_download.py
index 9283641e..7785616d 100644
--- a/tests/test_download.py
+++ b/tests/test_download.py
@@ -14,6 +14,7 @@
                                 cds_set_credentials_rcfile,
                                 cds_remove_credentials_raise,
                                 copernicusmarine_credentials,
+                                copernicusmarine_get_buffer,
                                 )
 import dfm_tools as dfmt
 import xarray as xr
@@ -165,6 +166,14 @@ def test_copernicusmarine_credentials():
     copernicusmarine_credentials()
 
 
+@pytest.mark.requiressecrets
+@pytest.mark.unittest
+def test_copernicusmarine_get_buffer_notfound():
+    dataset_id = 'cmems_obs-oc_glo_bgc-transp_my_l3-multi-4km_P1D'
+    buffer = copernicusmarine_get_buffer(dataset_id)
+    assert buffer == 0.5
+    
+
 @pytest.mark.requiressecrets
 @pytest.mark.unittest
 def test_download_cmems_my(tmp_path):