diff --git a/writer/HDF5Sum.cpp b/writer/HDF5Sum.cpp
index f632b3a0..2c278813 100644
--- a/writer/HDF5Sum.cpp
+++ b/writer/HDF5Sum.cpp
@@ -70,10 +70,14 @@ int main(int argc, char **argv) {
                     else image_out[pxl] += tmp;
                 }
             }
-            std::vector<SpotToSave> spots;
 
             auto image_size = compressor.Compress(output.data(), image_out);
-            dataFile.Write(output.data(), image_size, spots, i);
+            DataMessage message;
+            message.image.data = output.data();
+            message.image.size = image_size;
+            message.number = i;
+
+            dataFile.Write(message, i);
         }
     } catch (const JFJochException &e) {
         std::cerr << "Error: " << e.what() << std::endl;