diff --git a/tests/test_rio_blocks.py b/tests/test_rio_blocks.py
index 51397dd9..3101f1ae 100644
--- a/tests/test_rio_blocks.py
+++ b/tests/test_rio_blocks.py
@@ -20,7 +20,7 @@ def check_features_block_windows(features, src, bidx):
     ----------
     features : iter
         GeoJSON features.
-    src : RasterReader
+    src : DatasetReader
         Open input datasource.
 
     Returns