diff --git a/nlmod/read/ahn.py b/nlmod/read/ahn.py
index ec01c295..30575616 100644
--- a/nlmod/read/ahn.py
+++ b/nlmod/read/ahn.py
@@ -580,6 +580,8 @@ def _get_ahn_ellipsis(extent, identifier="AHN5_5M_M", **kwargs):
     das = []
     for tile in tqdm(tiles.index, desc=f"Downloading tiles of {identifier}"):
         url = tiles.at[tile, identifier]
+        if url == "nan":
+            continue
         if url.endswith(".zip"):
             path = url.split("/")[-1].replace(".zip", ".TIF")
             if path.lower().endswith(".tif.tif"):