diff --git a/Framework/AnalysisSupport/src/TTreePlugin.cxx b/Framework/AnalysisSupport/src/TTreePlugin.cxx
index 90b862e5fc8d1..28fd713112c94 100644
--- a/Framework/AnalysisSupport/src/TTreePlugin.cxx
+++ b/Framework/AnalysisSupport/src/TTreePlugin.cxx
@@ -208,7 +208,7 @@ auto readBoolValues = [](uint8_t* target, ReadOps& op, TBufferFile& rootBuffer)
   memset(target, 0, op.targetBuffer->size());
   int readLast = 0;
   while (readEntries < op.rootBranchEntries) {
-    auto beginValue = readLast;
+    auto beginValue = readEntries;
     readLast = op.branch->GetBulkRead().GetBulkEntries(readEntries, rootBuffer);
     int size = readLast * op.listSize;
     readEntries += readLast;