diff --git a/formats/geotiff_format.py b/formats/geotiff_format.py
index 338172b8af0d4cc2bf3eb47028d1b59ea5d327c1..d291e1a13fe318a1b0e2abb4b02438240475a1fa 100644
--- a/formats/geotiff_format.py
+++ b/formats/geotiff_format.py
@@ -7,6 +7,10 @@ import os
 def is_geotiff(resource, file_name):
     dataset = gdal.Open(file_name)
 
+    if not dataset:
+        resource["error"] = f"could not read file {file_name}"
+        return False
+
     geotransform = dataset.GetGeoTransform()
     default_transform = (0.0, 1.0, 0.0, 0.0, 0.0, 1.0)