diff --git a/autotest/gcore/cog.py b/autotest/gcore/cog.py
index 4b6e4b6a6aba..a56040170e05 100755
--- a/autotest/gcore/cog.py
+++ b/autotest/gcore/cog.py
@@ -328,7 +328,7 @@ def test_cog_creation_of_overviews_with_compression():
 
     ds_overview_b = gdal.Open("GTIFF_DIR:3:" + filename)
     assert ds_overview_b.GetMetadata("IMAGE_STRUCTURE")["COMPRESSION"] == "JPEG"
-    assert ds_overview_a.GetMetadata("IMAGE_STRUCTURE")["JPEG_QUALITY"] == "50"
+    assert ds_overview_b.GetMetadata("IMAGE_STRUCTURE")["JPEG_QUALITY"] == "50"
 
     ds_overview_a = None
     ds_overview_b = None