diff --git a/rapida/ntl/noaa/cmask.py b/rapida/ntl/noaa/cmask.py
index ab2a998..b230a38 100644
--- a/rapida/ntl/noaa/cmask.py
+++ b/rapida/ntl/noaa/cmask.py
@@ -327,9 +327,9 @@ def cloud_coverage(hdf_url: str, bbox: list) -> int:
         gdal.SetConfigOption('GDAL_SKIP', '')
         # On Linux, we use the native NetCDF driver
         base_ds = f'HDF5:"/vsicurl/{hdf_url}"'
-        mask_str = f'{base_ds}:CloudMaskBinary'
-        lon_str = f'{base_ds}:Longitude'
-        lat_str = f'{base_ds}:Latitude'
+        mask_str = f'{base_ds}://CloudMaskBinary'
+        lon_str = f'{base_ds}://Longitude'
+        lat_str = f'{base_ds}://Latitude'
 
     gdal.SetConfigOption('GDAL_HTTP_TIMEOUT', '600')
     gdal.SetConfigOption('GDAL_HTTP_MULTIPLEX', 'YES')