diff --git a/contrib/platform/src/com/sun/jna/platform/win32/WinNT.java b/contrib/platform/src/com/sun/jna/platform/win32/WinNT.java
index ba65d57dc9..ff75fcdaf5 100644
--- a/contrib/platform/src/com/sun/jna/platform/win32/WinNT.java
+++ b/contrib/platform/src/com/sun/jna/platform/win32/WinNT.java
@@ -23,6 +23,11 @@
  */
 package com.sun.jna.platform.win32;
 
+import java.lang.reflect.Field;
+import java.util.ArrayList;
+import java.util.Iterator;
+import java.util.List;
+
 import com.sun.jna.FromNativeContext;
 import com.sun.jna.IntegerType;
 import com.sun.jna.Memory;
@@ -3126,33 +3131,89 @@ public void read() {
     /**
      * Represents information about a NUMA node in a processor group.
      */
-    @FieldOrder({ "nodeNumber", "reserved", "groupMask" })
+    @FieldOrder({ "nodeNumber", "reserved", "groupCount", "groupMask", "groupMasks" })
     public static class NUMA_NODE_RELATIONSHIP extends SYSTEM_LOGICAL_PROCESSOR_INFORMATION_EX {
 
         /**
-         * Identifies the NUMA node. Valid values are {@code 0} to the highest
-         * NUMA node number inclusive. A non-NUMA multiprocessor system will
-         * report that all processors belong to one NUMA node.
+         * Identifies the NUMA node. Valid values are {@code 0} to the highest NUMA node
+         * number inclusive. A non-NUMA multiprocessor system will report that all
+         * processors belong to one NUMA node.
          */
         public int nodeNumber;
 
         /**
          * This member is reserved.
          */
-        public byte[] reserved = new byte[20];
+        public byte[] reserved = new byte[18];
+
+        /**
+         * The number of groups included in the GroupMasks array. This field was
+         * introduced in TBD Release Iron. On earlier versions, this value is always 0.
+         */
+        public short groupCount;
 
         /**
          * A {@link GROUP_AFFINITY} structure that specifies a group number and
-         * processor affinity within the group.
+         * processor affinity within the group. This member is only relevant if
+         * {@code groupCount} is 0.
          */
         public GROUP_AFFINITY groupMask;
 
+        /**
+         * An array of {@link GROUP_AFFINITY} structures that specifies a group number
+         * and processor affinity within the group. This member is only relevant if
+         * {@code groupCount} is 1 or greater.
+         */
+        public GROUP_AFFINITY[] groupMasks = new GROUP_AFFINITY[1];
+
         public NUMA_NODE_RELATIONSHIP() {
         }
 
         public NUMA_NODE_RELATIONSHIP(Pointer memory) {
             super(memory);
         }
+
+        /*
+         * Since the groupMasks array always has at least one element we copy it to the
+         * groupMask field for backwards compatibility in the case groupCount is 0 or 1.
+         * Otherwise we resize the array.
+         */
+        @Override
+        public void read() {
+            readField("groupCount");
+            if (groupCount > 1) {
+                groupMasks = new GROUP_AFFINITY[groupCount];
+            }
+            super.read();
+            // Copy first value from array to older version of structure
+            groupMask = groupMasks[0];
+        }
+
+        /*
+         * getFieldList and getFieldOrder are overridden because there are two versions
+         * of this structure. We will always populate the groupMasks field in the newer
+         * version, but we will copy groupMasks[0] to the groupMask field elsewhere for
+         * backwards compatibility.
+         */
+        @Override
+        protected List<Field> getFieldList() {
+            List<Field> fields = new ArrayList<Field>(super.getFieldList());
+            Iterator<Field> fieldIterator = fields.iterator();
+            while (fieldIterator.hasNext()) {
+                Field field = fieldIterator.next();
+                if ("groupMask".equals(field.getName())) {
+                    fieldIterator.remove();
+                }
+            }
+            return fields;
+        }
+
+        @Override
+        protected List<String> getFieldOrder() {
+            List<String> fieldOrder = new ArrayList<String>(super.getFieldOrder());
+            fieldOrder.remove("groupMask");
+            return fieldOrder;
+        }
     }
 
     /**