diff --git a/Tests/PDB/a_structure.cif b/Tests/PDB/a_structure.cif
index 3484a1ef6..589b1ed08 100644
--- a/Tests/PDB/a_structure.cif
+++ b/Tests/PDB/a_structure.cif
@@ -1,3 +1,4 @@
+data_a_structure
 loop_
 _atom_type.symbol 
 N