diff --git a/xclim/sdba/base.py b/xclim/sdba/base.py
index 2a1eabf90..0d40e716e 100644
--- a/xclim/sdba/base.py
+++ b/xclim/sdba/base.py
@@ -611,7 +611,7 @@ def _map_blocks(ds, **kwargs):  # noqa: C901
                     {
                         dim: chunks.get(dim)
                         for dim in reduced_dims
-                        if len(chunks.get(dim)) > 1
+                        if len(chunks.get(dim, [])) > 1
                     }
                 )
                 if badchunks: