diff --git a/contrib/platform/src/com/sun/jna/platform/linux/ErrNo.java b/contrib/platform/src/com/sun/jna/platform/linux/ErrNo.java
index 7469ad37b3..95b59fc233 100644
--- a/contrib/platform/src/com/sun/jna/platform/linux/ErrNo.java
+++ b/contrib/platform/src/com/sun/jna/platform/linux/ErrNo.java
@@ -1,3 +1,26 @@
+/* Copyright (c) 2020 Daniel Widdis, All Rights Reserved
+ *
+ * The contents of this file is dual-licensed under 2
+ * alternative Open Source/Free licenses: LGPL 2.1 or later and
+ * Apache License 2.0. (starting with JNA version 4.0.0).
+ *
+ * You can freely decide which license you want to apply to
+ * the project.
+ *
+ * You may obtain a copy of the LGPL License at:
+ *
+ * http://www.gnu.org/licenses/licenses.html
+ *
+ * A copy is also included in the downloadable source code package
+ * containing JNA, in file "LGPL2.1".
+ *
+ * You may obtain a copy of the Apache License at:
+ *
+ * http://www.apache.org/licenses/
+ *
+ * A copy is also included in the downloadable source code package
+ * containing JNA, in file "AL2.0".
+ */
 package com.sun.jna.platform.linux;
 
 import com.sun.jna.Native;
diff --git a/contrib/platform/test/com/sun/jna/platform/linux/LibRTTest.java b/contrib/platform/test/com/sun/jna/platform/linux/LibRTTest.java
index 7743ef6b33..32800ba69c 100644
--- a/contrib/platform/test/com/sun/jna/platform/linux/LibRTTest.java
+++ b/contrib/platform/test/com/sun/jna/platform/linux/LibRTTest.java
@@ -44,6 +44,7 @@
 import com.sun.jna.Pointer;
 import com.sun.jna.platform.unix.LibCAPI.off_t;
 import com.sun.jna.platform.unix.LibCAPI.size_t;
+import com.sun.jna.platform.unix.LibCUtil;
 
 import junit.framework.TestCase;
 
@@ -63,8 +64,9 @@ public void testMmapToShm() throws IOException {
         assertNotEquals("Failed to shm_open " + share + ". Error: " + Native.getLastError(), -1, fd);
         try {
             // Multiply by 4 to handle all possible encodings
-            size_t length = new size_t(4 * (share.length() + 1));
-            off_t truncLen = new off_t(4 * (share.length() + 1));
+            int bufLen = 4 * (share.length() + 1);
+            size_t length = new size_t(bufLen);
+            off_t truncLen = new off_t(bufLen);
             // Allocate memory to the share (fills with null bytes)
             int ret = LIBC.ftruncate(fd, truncLen);
             assertNotEquals("Failed to ftruncate. Error: " + Native.getLastError(), -1, ret);
@@ -93,8 +95,8 @@ public void testMmapToShm() throws IOException {
             // So let's not recreate it, instead get a file descriptor to the existing share
             fd = LIBRT.shm_open(share, O_RDWR, S_IRWXU);
             assertNotEquals("Failed to re-open " + share + ". Error: " + Native.getLastError(), -1, fd);
-            // Map another pointer to the share.
-            Pointer q = LIBC.mmap(null, length, PROT_READ | PROT_WRITE, MAP_SHARED, fd, off_t.ZERO);
+            // Map another pointer to the share. Use the util version to test it
+            Pointer q = LibCUtil.mmap(null, bufLen, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
             assertNotEquals("Failed mmap to existing share. Error: " + Native.getLastError(), MAP_FAILED, q);
             // Close the file descriptor
             ret = LIBC.close(fd);