diff --git a/CHANGES.md b/CHANGES.md
index a0d516b6b1..ce9d6b9810 100755
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -7,11 +7,72 @@ Release 4.2 (Next)
 
 Features
 --------
-* [#452](https://github.com/twall/jna/pull/452): Added Mac OS X System.B library at `com.sun.jna.platform.mac.SystemB`  including support for `sysctl`, `sysctlbyname`, `sysctlnametomib`, `mach_host_self`, `host_page_size`, `host_statistics` and `host_statistics64` - [@dbwiddis](https://github.com/dbwiddis).
-* [#446](https://github.com/twall/jna/pull/446): Added `com.sun.jna.platform.win32.Advapi32.GetNamedSecurityInfo`, `SetNamedSecurityInfo`, `GetSecurityDescriptorLength`, `IsValidSecurityDescriptor`, `IsValidAcl` - [@amarcionek](https://github.com/amarcionek).
-* [#387](https://github.com/twall/jna/pull/397): Use of interfaces and annotations to provide easier implementation of COM interfaces (with `InvocationHandler`) - [@dhakehurst](https://github.com/dhakehurst).
-* [#387](https://github.com/twall/jna/pull/397): Support for COM event callbacks - [@dhakehurst](https://github.com/dhakehurst).
-* [#387](https://github.com/twall/jna/pull/397): Support for COM interface discovery by iteration over `RunningObjectTable` - [@dhakehurst](https://github.com/dhakehurst).
+* [#526](https://github.com/java-native-access/jna/pull/526): Added initialization and conversion between Windows SYSTEMTIME and Java Calendar - [@lgoldstein](https://github.com/lgoldstein).
+* [#532](https://github.com/java-native-access/jna/pull/529): Added `com.sun.jna.platform.win32.Mpr`, `com.sun.jna.platform.win32.LmShare`, and `com.sun.jna.platform.win32.Winnetwk` - [@amarcionek](https://github.com/amarcionek).
+* [#532](https://github.com/java-native-access/jna/pull/529): Added `ACCESS_*` definitions to `com.sun.jna.platform.win32.LmAccess` - [@amarcionek](https://github.com/amarcionek).
+* [#532](https://github.com/java-native-access/jna/pull/529): Added `NetShareAdd` and `NetShareDel` to `com.sun.jna.platform.win32.Netapi32` - [@amarcionek](https://github.com/amarcionek).
+* [#535](https://github.com/java-native-access/jna/pull/535): Added `CreateProcessWithLogonW` to `com.sun.jna.platform.win32.Advapi32` - [@mlfreeman2](https://github.com/mlfreeman2).
+* [#535](https://github.com/java-native-access/jna/pull/535): Added `CertAddEncodedCertificateToSystemStore` to `com.sun.jna.platform.win32.Crypt32` - [@mlfreeman2](https://github.com/mlfreeman2).
+* [#535](https://github.com/java-native-access/jna/pull/535): Added `BitBlt` to `com.sun.jna.platform.win32.GDI32`, Added `com.sun.jna.platform.win32.GDI32Util` and added `getScreenshot()` to it - [@mlfreeman2](https://github.com/mlfreeman2).
+* [#535](https://github.com/java-native-access/jna/pull/535): Added `SHEmptyRecycleBin`, `ShellExecuteEx` to `com.sun.jna.platform.win32.Shell32` - [@mlfreeman2](https://github.com/mlfreeman2).
+* [#535](https://github.com/java-native-access/jna/pull/535): Added `GetDesktopWindow` to `com.sun.jna.platform.win32.User32` - [@mlfreeman2](https://github.com/mlfreeman2).
+* [#540](https://github.com/java-native-access/jna/pull/539): Added Missing Windows kernel32 method: QueryFullProcessImageName - [@yossieilaty](https://github.com/yossieilaty).
+* [#543](https://github.com/java-native-access/jna/pull/543): Added `ProcessIdToSessionId`, `LoadLibraryEx`, `FreeLibrary` and `Find/Load/Lock/SizeofResource` to `com.sun.jna.platform.win32.Kernel32` - [@mlfreeman2](https://github.com/mlfreeman2).
+* [#545](https://github.com/java-native-access/jna/pull/545): Added `EnumResourceTypes` and `EnumResourceNames` to `com.sun.jna.platform.win32.Kernel32` - [@mlfreeman2](https://github.com/mlfreeman2).
+* [#547](https://github.com/java-native-access/jna/pull/547): Added `GetSystemTimes` to `com.sun.jna.platform.win32.Kernel32` - [@dbwiddis](https://github.com/dbwiddis).
+* [#548](https://github.com/java-native-access/jna/pull/548): Return 64-bit unsigned integer from `com.sun.jna.platform.win32.WinBase.FILETIME` - [@dbwiddis](https://github.com/dbwiddis).
+* [#524](https://github.com/java-native-access/jna/pull/524): Added IShellFolder interface plus necessary utility functions to Windows platform, and a sample for enumerating objects in My Computer - [@lwahonen](https://github.com/lwahonen).
+* [#471](https://github.com/java-native-access/jna/issues/471): Determine size of native `bool` - [@twall](https://github.com/twall).
+* [#484](https://github.com/java-native-access/jna/pull/484): Added `XFetchName` to `X11` interface - [@pinaf](https://github.com/pinaf).
+* [#554](https://github.com/java-native-access/jna/pull/554): Initial code for a few Unix 'libc' API(s) [@lgoldstein](https://github.com/lgoldstein)
+* [#552](https://github.com/java-native-access/jna/pull/552): Added `Module32FirstW` and `Module32NextW` to `com.sun.jna.platform.win32.Kernel32` (and helper to `com.sun.jna.platform.win32.Kernel32Util`) and `MODULEENTRY32W` structure to `com.sun.jna.platform.win32.Tlhelp32` - [@mlfreeman2](https://github.com/mlfreeman2).
+* [#564](https://github.com/java-native-access/jna/pull/564): Use generic definition of Native#loadLibrary [@lgoldstein](https://github.com/lgoldstein)
+* [#562](https://github.com/java-native-access/jna/pull/562): Added `com.sun.jna.platform.win32.VersionUtil` with `getFileVersionInfo` utility method to get file major, minor, revision, and build version parts - [@mlfreeman2](https://github.com/mlfreeman2).
+* [#563](https://github.com/java-native-access/jna/pull/563): Added `com.sun.jna.platform.win32.Wininet` with the following 4 methods: `FindFirstUrlCacheEntry`, `DeleteUrlCacheEntry`, `FindCloseUrlCache`, `FindNextUrlCacheEntry`, and the `INTERNET_CACHE_ENTRY_INFO` structure, and a helper in `com.sun.jna.platform.win32.WininetUtil` for parsing WinInet's cache - [@mlfreeman2](https://github.com/mlfreeman2).
+* [#567](https://github.com/java-native-access/jna/pull/567): Added `PrintWindow`, `IsWindowEnabled`, `IsWindow`, `FindWindowEx`, `GetAncestor`, `GetCursorPos`, `SetCursorPos`, `SetWinEventHook`, `UnhookWinEvent`, `CopyIcon`, and `GetClassLong` to `com.sun.jna.platform.win32.User32` and supporting constants to `com.sun.jna.platform.win32.WinUser` - [@mlfreeman2](https://github.com/mlfreeman2).
+* [#573](https://github.com/java-native-access/jna/pull/573): Added `EnumProcessModules`, `GetModuleInformation`, and `GetProcessImageFileName` to `com.sun.jna.platform.win32.Psapi` and added `ExtractIconEx` to `com.sun.jna.platform.win32.Shell32` - [@mlfreeman2](https://github.com/mlfreeman2).
+* [#574](https://github.com/java-native-access/jna/pull/574): Using static final un-modifiable List of field names for structure(s) - [@lgoldstein](https://github.com/lgoldstein).
+* [#577](https://github.com/java-native-access/jna/pull/577): Apply generic definitions wherever applicable - [@lgoldstein](https://github.com/lgoldstein).
+* [#569](https://github.com/java-native-access/jna/pull/569): Added `com.sun.jna.platform.win32.Winspool.PRINTER_INFO_2` support. Added GetPrinter and ClosePrinter functions in `com.sun.jna.platform.win32.Winspool` - [@IvanRF](https://github.com/IvanRF).
+* [#583](https://github.com/java-native-access/jna/pull/583): Added printer attributes and status - [@IvanRF](https://github.com/IvanRF).
+* [#589](https://github.com/java-native-access/jna/pull/589): Use MethodResultContext in direct mapping (as done in interface mapping) - [@marco2357](https://github.com/marco2357).
+
+Bug Fixes
+---------
+* [#549](https://github.com/java-native-access/jna/pull/549): Fixed bug in types derived from XID - [@twall](https://github.com/twall).
+* [#536](https://github.com/java-native-access/jna/pull/536): Fixed bug in determining the Library and options associated with types defined outside of a Library - [@twall](https://github.com/twall).
+* [#531](https://github.com/java-native-access/jna/pull/531): Ensure direct-mapped callbacks use the right calling convention - [@twall](https://github.com/twall).
+* [#566](https://github.com/java-native-access/jna/pull/566): Fix return type of Native#loadLibrary to match unconstrained generic [@lgoldstein](https://github.com/lgoldstein)
+* [#584](https://github.com/java-native-access/jna/pull/584): Promote float varargs to double - [@marco2357](https://github.com/marco2357).
+* [#588](https://github.com/java-native-access/jna/pull/588): Fix varargs calls on arm - [@twall](https://github.com/twall).
+* [#593](https://github.com/java-native-access/jna/pull/593): Improve binding of TypeLib bindings - [@matthiasblaesing](https://github.com/matthiasblaesing).
+
+Release 4.2.1
+=============
+
+Features
+--------
+* [#504](https://github.com/java-native-access/jna/pull/504): Add support for linux-sparcv9 - [@alexvsimon](https://github.com/alexvsimon).
+* [#510](https://github.com/java-native-access/jna/pull/510): Added `GetCommState`, `GetCommTimeouts` `SetCommState` and `SetCommTimeouts` to `com.sun.jna.platform.win32.Kernel32`. Added `DCB` structure to `com.sun.jna.platform.win32.WinBase` - [@MBollig](https://github.com/MBollig).
+* [#512](https://github.com/java-native-access/jna/pull/512): Make loading debug flags mutable [@lwahonen](https://github.com/lwahonen).
+* [#514](https://github.com/java-native-access/jna/pull/514): Added `host_processor_info` to `com.sun.jna.platform.mac.SystemB`  - [@dbwiddis](https://github.com/dbwiddis).
+* [#519](https://github.com/java-native-access/jna/pull/519): Added JNA functional overview - [@twall](https://github.com/twall).
+* [#528](https://github.com/java-native-access/jna/pull/528): Added idea-jar ant task that creates a convenience jar that contains all native dispatch libraries - [@lwahonen](https://github.com/lwahonen).
+
+Bug Fixes
+---------
+* [#515](https://github.com/java-native-access/jna/issues/515): Update linux-arm natives omitted in 4.2 [@twall](https://github.com/twall).
+
+Release 4.2
+===========
+
+Features
+--------
+* [#452](https://github.com/java-native-access/jna/pull/452): Added Mac OS X System.B library at `com.sun.jna.platform.mac.SystemB`  including support for `sysctl`, `sysctlbyname`, `sysctlnametomib`, `mach_host_self`, `host_page_size`, `host_statistics` and `host_statistics64` - [@dbwiddis](https://github.com/dbwiddis).
+* [#446](https://github.com/java-native-access/jna/pull/446): Added `com.sun.jna.platform.win32.Advapi32.GetNamedSecurityInfo`, `SetNamedSecurityInfo`, `GetSecurityDescriptorLength`, `IsValidSecurityDescriptor`, `IsValidAcl` - [@amarcionek](https://github.com/amarcionek).
+* [#387](https://github.com/java-native-access/jna/pull/397): Use of interfaces and annotations to provide easier implementation of COM interfaces (with `InvocationHandler`) - [@dhakehurst](https://github.com/dhakehurst).
+* [#387](https://github.com/java-native-access/jna/pull/397): Support for COM event callbacks - [@dhakehurst](https://github.com/dhakehurst).
+* [#387](https://github.com/java-native-access/jna/pull/397): Support for COM interface discovery by iteration over `RunningObjectTable` - [@dhakehurst](https://github.com/dhakehurst).
 * Updated AIX natives and build - [@twall](https://github.com/twall).
 * [#290](https://github.com/twall/jna/pull/290): Improved the stacktrace for the exceptions thrown by `com.sun.jna.Structure` - [@ebourg](https://github.com/ebourg).
 * [#332](https://github.com/twall/jna/pull/332): Added Win32 Monitor Configuration API in `com.sun.jna.platform.win32.Dxva2` - [@msteiger](https://github.com/msteiger).
diff --git a/native/dispatch.c b/native/dispatch.c
index 4a5969e68e..14e98c6007 100644
--- a/native/dispatch.c
+++ b/native/dispatch.c
@@ -97,6 +97,8 @@ static int _protect;
 
 #ifdef __cplusplus
 extern "C" {
+#else
+#include <stdbool.h>
 #endif
 
 #define MEMCPY(ENV,D,S,L) do {     \
@@ -2669,6 +2671,7 @@ Java_com_sun_jna_Native_sizeof(JNIEnv *env, jclass UNUSED(cls), jint type)
   case com_sun_jna_Native_TYPE_LONG: return sizeof(long);
   case com_sun_jna_Native_TYPE_WCHAR_T: return sizeof(wchar_t);
   case com_sun_jna_Native_TYPE_SIZE_T: return sizeof(size_t);
+  case com_sun_jna_Native_TYPE_BOOL: return sizeof(bool);
   default:
     {
       char msg[MSG_SIZE];
diff --git a/src/com/sun/jna/Native.java b/src/com/sun/jna/Native.java
index 445a60f60a..de6e75d397 100644
--- a/src/com/sun/jna/Native.java
+++ b/src/com/sun/jna/Native.java
@@ -118,11 +118,14 @@ public void uncaughtException(Callback c, Throwable e) {
     public static final int WCHAR_SIZE;
     /** Size of a native <code>size_t</code> type, in bytes. */
     public static final int SIZE_T_SIZE;
+    /** Size of a native <code>bool</code> type (C99 and later), in bytes. */
+    public static final int BOOL_SIZE;
 
     private static final int TYPE_VOIDP = 0;
     private static final int TYPE_LONG = 1;
     private static final int TYPE_WCHAR_T = 2;
     private static final int TYPE_SIZE_T = 3;
+    private static final int TYPE_BOOL = 4;
 
     static final int MAX_ALIGNMENT;
     static final int MAX_PADDING;
@@ -137,6 +140,7 @@ public static float parseVersion(String v) {
         LONG_SIZE = sizeof(TYPE_LONG);
         WCHAR_SIZE = sizeof(TYPE_WCHAR_T);
         SIZE_T_SIZE = sizeof(TYPE_SIZE_T);
+        BOOL_SIZE = sizeof(TYPE_BOOL);
 
         // Perform initialization of other JNA classes until *after*
         // initializing the above final fields
@@ -1103,8 +1107,7 @@ public static int getNativeSize(Class cls) {
         if (NativeMapped.class.isAssignableFrom(cls)) {
             cls = NativeMappedConverter.getInstance(cls).nativeType();
         }
-        // boolean defaults to 32 bit integer if not otherwise mapped
-        if (cls == boolean.class || cls == Boolean.class) return 4;
+        if (cls == boolean.class || cls == Boolean.class) return BOOL_SIZE;
         if (cls == byte.class || cls == Byte.class) return 1;
         if (cls == short.class || cls == Short.class) return 2;
         if (cls == char.class || cls == Character.class) return WCHAR_SIZE;
diff --git a/src/com/sun/jna/Structure.java b/src/com/sun/jna/Structure.java
index d8525da173..af5f3c3b2b 100644
--- a/src/com/sun/jna/Structure.java
+++ b/src/com/sun/jna/Structure.java
@@ -1747,8 +1747,10 @@ private static class FFITypes {
             typeInfoMap.put(Pointer.class, FFITypes.ffi_type_pointer);
             typeInfoMap.put(String.class, FFITypes.ffi_type_pointer);
             typeInfoMap.put(WString.class, FFITypes.ffi_type_pointer);
-            typeInfoMap.put(boolean.class, FFITypes.ffi_type_uint32);
-            typeInfoMap.put(Boolean.class, FFITypes.ffi_type_uint32);
+            Pointer btype = Native.BOOL_SIZE == 1
+                ? FFITypes.ffi_type_uint8 : FFITypes.ffi_type_uint32
+            typeInfoMap.put(boolean.class, FFITypes.btype);
+            typeInfoMap.put(Boolean.class, FFITypes.btype);
         }
         // From ffi.h
         private static final int FFI_TYPE_STRUCT = 13;
diff --git a/test/com/sun/jna/NativeTest.java b/test/com/sun/jna/NativeTest.java
index 075e0e5d21..29d9cf92f3 100644
--- a/test/com/sun/jna/NativeTest.java
+++ b/test/com/sun/jna/NativeTest.java
@@ -111,6 +111,10 @@ public void testCustomizeDefaultStringEncoding() {
         }
     }
 
+    public void testSizeof() {
+        assertEquals("Wrong bool size", 1, Native.BOOL_SIZE);
+    }
+
     public static interface TestLib extends Library {
         interface VoidCallback extends Callback {
             void callback();