diff --git a/src/changes/changes.xml b/src/changes/changes.xml
index 621aab56a..79382ba80 100644
--- a/src/changes/changes.xml
+++ b/src/changes/changes.xml
@@ -54,6 +54,9 @@ If the output is not quite correct, check for invisible trailing spaces!
     </release>
 
     <release version="4.0" date="XXXX-XX-XX" description="">
+      <action dev="tn" type="update" issue="MATH-760" due-to="sebb">
+        Field "windowSize" in "DescriptiveStatistics" has been made private.
+      </action>
       <action dev="sebb" type="add" issue="MATH-1198">
         Simplified "FastMath#exp(double)" in order to avoid a potential
         Java 1.5 JIT bug when calling with negative infinity as argument.
diff --git a/src/main/java/org/apache/commons/math4/stat/descriptive/DescriptiveStatistics.java b/src/main/java/org/apache/commons/math4/stat/descriptive/DescriptiveStatistics.java
index b1aa6d515..85f41d6fa 100644
--- a/src/main/java/org/apache/commons/math4/stat/descriptive/DescriptiveStatistics.java
+++ b/src/main/java/org/apache/commons/math4/stat/descriptive/DescriptiveStatistics.java
@@ -73,7 +73,7 @@ public class DescriptiveStatistics implements StatisticalSummary, Serializable {
     private static final String SET_QUANTILE_METHOD_NAME = "setQuantile";
 
     /** hold the window size **/
-    protected int windowSize = INFINITE_WINDOW;
+    private int windowSize = INFINITE_WINDOW;
 
     /**
      *  Stored data values