diff --git a/python/obitools3/uri/decode.pyx b/python/obitools3/uri/decode.pyx
index c6e2cab..5f9288e 100755
--- a/python/obitools3/uri/decode.pyx
+++ b/python/obitools3/uri/decode.pyx
@@ -179,6 +179,9 @@ def open_uri(uri,
     cdef dict qualifiers
     cdef DMS default_dms
     
+    if urib is None:
+        urib = b""
+    
     # Reformat URI if it was built with autocomplete
     urib = urib.replace(b".obidms", b"")
     urib = urib.replace(b".obiview", b"")