diff --git a/src/DataVampire.cpp b/src/DataVampire.cpp
index 2d7fe92d697a425b37fa6394798dd3238e13594b..cc643c1853e84c35d109d8c9a301b9f4bdcd8861 100644
--- a/src/DataVampire.cpp
+++ b/src/DataVampire.cpp
@@ -2430,6 +2430,7 @@ void DataVampire::process_2D(int32_t cache_idx, int32_t auto_bck_samples)
 		cache_buffer[cache_idx].validvalues[i] = valid_values;
 
 		if (i == 0) {
+			*attr_Sum_read =  cache_buffer[cache_idx].sum[i];
 			*attr_Mean_read =  cache_buffer[cache_idx].mean[i];
 			*attr_HorPos_read =  cache_buffer[cache_idx].horpos[i];			
 			*attr_VerPos_read =  cache_buffer[cache_idx].verpos[i];