diff --git a/Code/BasicFilters/otbLabelImageRegionMergingFilter.txx b/Code/BasicFilters/otbLabelImageRegionMergingFilter.txx
index 4d99301b0e095ade1ab4670fd9c559600343c830..2382545dd12bba038cd98001bafe7a99dc68ec03 100644
--- a/Code/BasicFilters/otbLabelImageRegionMergingFilter.txx
+++ b/Code/BasicFilters/otbLabelImageRegionMergingFilter.txx
@@ -189,7 +189,7 @@ LabelImageRegionMergingFilter<TInputLabelImage, TInputSpectralImage, TOutputLabe
             att.maxValue[comp] = std::max(currentObjectAttributes.maxValue[comp], adjacentObjectAttributes.maxValue[comp]);
             }
           // Merge objects
-          if(labelIt->second->Size() >= adjLabelObject->Size())
+          if(labelObject->Size() >= adjLabelObject->Size())
             {
             m_LabelMap->MergeLabels(labelIt->first, adjLabel);
             m_LabelMap->GetLabelObject(labelIt->first)->SetAttribute(att);