diff --git a/bam/blend/blendfile.py b/bam/blend/blendfile.py
index 5b49959..5903338 100644
--- a/bam/blend/blendfile.py
+++ b/bam/blend/blendfile.py
@@ -796,8 +796,8 @@ class DNAStruct:
             else:
                 return DNA_IO.write_bytes(handle, value, dna_name.array_size)
         else:
-            raise NotImplementedError("Setting %r is not yet supported" %
-                    dna_type[0], dna_name, dna_type)
+            raise NotImplementedError("Setting %r is not yet supported for %r" %
+                                      (dna_type, dna_name), dna_name, dna_type)
 
 
 class DNA_IO: