diff --git a/src/main/java/org/apache/commons/math/stat/inference/ChiSquareTestImpl.java b/src/main/java/org/apache/commons/math/stat/inference/ChiSquareTestImpl.java
index 07b9cd883..407b082ea 100644
--- a/src/main/java/org/apache/commons/math/stat/inference/ChiSquareTestImpl.java
+++ b/src/main/java/org/apache/commons/math/stat/inference/ChiSquareTestImpl.java
@@ -36,6 +36,9 @@ import org.apache.commons.math.util.FastMath;
  */
 public class ChiSquareTestImpl implements UnknownDistributionChiSquareTest {
 
+    /** Distribution used to compute inference statistics. */
+    private ChiSquaredDistribution distribution;
+
     /**
      * Construct a ChiSquareTestImpl
      */
@@ -112,7 +115,7 @@ public class ChiSquareTestImpl implements UnknownDistributionChiSquareTest {
      */
     public double chiSquareTest(double[] expected, long[] observed)
         throws MathException {
-        ChiSquaredDistributionImpl distribution = new ChiSquaredDistributionImpl(expected.length - 1.0);
+        distribution = new ChiSquaredDistributionImpl(expected.length - 1.0);
         return 1.0 - distribution.cumulativeProbability(
             chiSquare(expected, observed));
     }
@@ -186,7 +189,7 @@ public class ChiSquareTestImpl implements UnknownDistributionChiSquareTest {
     throws MathException {
         checkArray(counts);
         double df = ((double) counts.length -1) * ((double) counts[0].length - 1);
-        ChiSquaredDistributionImpl distribution = new ChiSquaredDistributionImpl(df);
+        distribution = new ChiSquaredDistributionImpl(df);
         return 1 - distribution.cumulativeProbability(chiSquare(counts));
     }
 
@@ -280,7 +283,7 @@ public class ChiSquareTestImpl implements UnknownDistributionChiSquareTest {
      */
     public double chiSquareTestDataSetsComparison(long[] observed1, long[] observed2)
         throws MathException {
-        ChiSquaredDistributionImpl distribution = new ChiSquaredDistributionImpl((double) observed1.length - 1);
+        distribution = new ChiSquaredDistributionImpl((double) observed1.length - 1);
         return 1 - distribution.cumulativeProbability(
                 chiSquareDataSetsComparison(observed1, observed2));
     }
@@ -390,4 +393,14 @@ public class ChiSquareTestImpl implements UnknownDistributionChiSquareTest {
         }
     }
 
+    /**
+     * Modify the distribution used to compute inference statistics.
+     *
+     * @param value
+     *            the new distribution
+     * @since 1.2
+     */
+    public void setDistribution(ChiSquaredDistribution value) {
+        distribution = value;
+    }
 }
diff --git a/src/site/xdoc/changes.xml b/src/site/xdoc/changes.xml
index ecab662ef..8f7af9139 100644
--- a/src/site/xdoc/changes.xml
+++ b/src/site/xdoc/changes.xml
@@ -52,10 +52,6 @@ The <action> type attribute can be add,update,fix,remove.
     If the output is not quite correct, check for invisible trailing spaces!
      -->
     <release version="3.0" date="TBD" description="TBD">
-      <action dev="sebb" type="fix" issue="MATH-506">
-          The static field ChiSquareTestImpl.distribution serves no purpose.
-          Removed setter and static field, and made other instances local variables. 
-      </action>
       <action dev="sebb" type="fix" issue="MATH-505">
           TestUtils is thread-hostile. Remove getters and setters, and make static variables final.
       </action>