diff --git a/python/merge_regions.py b/python/merge_regions.py
index dd1d7aa83dff93326dc537ee6ec0313af3fdc051..42035c08412e9d038dec3f46a94b3593dc30a89e 100755
--- a/python/merge_regions.py
+++ b/python/merge_regions.py
@@ -82,6 +82,7 @@ def main():
         for hn in histonames:
             master_histo = input_file.Get(hn)
             other_histos = [input_file.Get(hn.replace(master_region, r)) for r in other_regions]
+            master_histo.SetName(master_histo.GetName().replace(master_region, target_region))
             master_histo.SetDirectory(output_file)
             for h in other_histos:
                 master_histo.Add(h)