diff --git a/src/stats/model/histogram.cc b/src/stats/model/histogram.cc
index 2e58e4af9..b91e11982 100644
--- a/src/stats/model/histogram.cc
+++ b/src/stats/model/histogram.cc
@@ -71,7 +71,7 @@ Histogram::SetDefaultBinWidth(double binWidth)
 }
 
 uint32_t
-Histogram::GetBinCount(uint32_t index)
+Histogram::GetBinCount(uint32_t index) const
 {
     NS_ASSERT(index < m_histogram.size());
     return m_histogram[index];
diff --git a/src/stats/model/histogram.h b/src/stats/model/histogram.h
index 7d5dedac9..c2fd5a682 100644
--- a/src/stats/model/histogram.h
+++ b/src/stats/model/histogram.h
@@ -93,7 +93,7 @@ class Histogram
      * \param index the bin index
      * \return the number of data added to the bin
      */
-    uint32_t GetBinCount(uint32_t index);
+    uint32_t GetBinCount(uint32_t index) const;
 
     // Method for adding values
     /**