diff --git a/src/image/Image.cc b/src/image/Image.cc
index fd983e6d7b..d59f00f7e8 100644
--- a/src/image/Image.cc
+++ b/src/image/Image.cc
@@ -661,7 +661,7 @@ int Image::disk_attribute(VectorAttribute * disk, int * index)
         break;
 
         case DATABLOCK:
-            prefix += static_cast<char>(('d'+ *index));
+            prefix += static_cast<char>(('e'+ *index));
             *index  = *index + 1;
         break;