diff --git a/CHANGES.md b/CHANGES.md
index 2d900ee918..c7fd6bad70 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -15,6 +15,7 @@ Bug Fixes
 ---------
 * [#1452](https://github.com/java-native-access/jna/issues/1452): Fix memory allocation/handling for error message generation in native library code (`dispatch.c`) - [@matthiasblaesing](https://github.com/matthiasblaesing).
 * [#1460](https://github.com/java-native-access/jna/issues/1460): Fix win32 variant date conversion in DST offest window and with millisecond values - [@eranl](https://github.com/eranl).
+* [#1472](https://github.com/java-native-access/jna/issues/1472): Fix incorrect bitmask in `c.s.j.Pointer#createConstant(int)` - [@dbwiddis](https://github.com/dbwiddis).
 
 Release 5.12.1
 ==============
diff --git a/contrib/platform/src/com/sun/jna/platform/win32/COM/util/ProxyObject.java b/contrib/platform/src/com/sun/jna/platform/win32/COM/util/ProxyObject.java
index 1a403a39fc..85017e8c1e 100644
--- a/contrib/platform/src/com/sun/jna/platform/win32/COM/util/ProxyObject.java
+++ b/contrib/platform/src/com/sun/jna/platform/win32/COM/util/ProxyObject.java
@@ -189,7 +189,7 @@ public boolean equals(Object arg) {
     @Override
     public int hashCode() {
         long id = this.getUnknownId();
-        return (int) ((id >>> 32) & 0xFFFFFFFF) + (int) (id & 0xFFFFFFFF);
+        return (int) ((id >>> 32) + (id & 0xFFFFFFFFL));
     }
 
     @Override
diff --git a/src/com/sun/jna/Pointer.java b/src/com/sun/jna/Pointer.java
index 1f85885110..1a3fe5d60f 100644
--- a/src/com/sun/jna/Pointer.java
+++ b/src/com/sun/jna/Pointer.java
@@ -60,7 +60,7 @@ public static final Pointer createConstant(long peer) {
         systems.
      */
     public static final Pointer createConstant(int peer) {
-        return new Opaque((long)peer & 0xFFFFFFFF);
+        return new Opaque(peer & 0xFFFFFFFFL);
     }
 
     /** Pointer value of the real native pointer. Use long to be 64-bit safe.
@@ -112,7 +112,7 @@ public boolean equals(Object o) {
 
     @Override
     public int hashCode() {
-        return (int)((peer >>> 32) + (peer & 0xFFFFFFFF));
+        return (int) ((peer >>> 32) + (peer & 0xFFFFFFFFL));
     }
 
 
diff --git a/test/com/sun/jna/PointerTest.java b/test/com/sun/jna/PointerTest.java
index bce88fbf7b..a457b5f9c4 100644
--- a/test/com/sun/jna/PointerTest.java
+++ b/test/com/sun/jna/PointerTest.java
@@ -25,10 +25,11 @@
 
 package com.sun.jna;
 
+import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
 import java.lang.reflect.Modifier;
-import java.lang.reflect.InvocationTargetException;
 import java.util.Arrays;
+
 import junit.framework.TestCase;
 
 
@@ -174,10 +175,13 @@ public void testReadPointerArray() {
 
     public void testCreateConstantPointer() {
         Pointer p = Pointer.createConstant(0xFFFFFFFF);
-        assertEquals("Wrong peer value", p.peer, 0xFFFFFFFF);
+        assertEquals("Wrong peer value", p.peer, 0xFFFFFFFFL);
 
-        p = Pointer.createConstant(-1);
+        p = Pointer.createConstant(-1L);
         assertEquals("Wrong peer value", p.peer, -1);
+
+        p = Pointer.createConstant(0x80000000);
+        assertEquals("createConstant(int) should avoid setting any high bits", 0, Pointer.nativeValue(p) >>> 32);
     }
 
     public void testReadStringArrayNULLElement() {