diff --git a/arangod/VocBase/document-collection.c b/arangod/VocBase/document-collection.c
index 6361a4fd74..bb70d1246c 100644
--- a/arangod/VocBase/document-collection.c
+++ b/arangod/VocBase/document-collection.c
@@ -1484,15 +1484,17 @@ static bool OpenIterator (TRI_df_marker_t const* marker, void* data, TRI_datafil
       // update the header info
       UpdateHeader(datafile, marker, found, &update);
       update._validTo = 0;
-
       // update the datafile info
       dfi = TRI_FindDatafileInfoPrimaryCollection(primary, found->_fid);
 
       if (dfi != NULL) {
         size_t length = LengthDataMasterPointer(found);
 
+/*
+        issue #411: if we decrease here, the counts might get negative!
         dfi->_numberAlive -= 1;
         dfi->_sizeAlive -= length;
+*/
 
         dfi->_numberDead += 1;
         dfi->_sizeDead += length;
@@ -1504,7 +1506,6 @@ static bool OpenIterator (TRI_df_marker_t const* marker, void* data, TRI_datafil
         dfi->_numberAlive += 1;
         dfi->_sizeAlive += LengthDataMasterPointer(&update);
       }
-
       // update immediate indexes
       UpdateImmediateIndexes(collection, found, &update);
     }