diff --git a/pixell/enmap.py b/pixell/enmap.py
index ae715c3..b3cf222 100644
--- a/pixell/enmap.py
+++ b/pixell/enmap.py
@@ -402,6 +402,7 @@ def has_wcs(m):
 		elif isinstance(arr, list) and len(arr) > 0 and has_wcs(arr[0]):
 			wcs = arr[0].wcs
 		else:
+			warnings.warn("An empty WCS with default values is being attached, since no WCS was specified. This may result in unexpected results.")
 			wcs = wcsutils.WCS(naxis=2)
 	if copy:
 		arr = np.asanyarray(arr, dtype=dtype).copy()