diff --git a/Headers/Additions/GNUstepBase/GSMime.h b/Headers/Additions/GNUstepBase/GSMime.h
index 908a0795c..e12f5b94f 100644
--- a/Headers/Additions/GNUstepBase/GSMime.h
+++ b/Headers/Additions/GNUstepBase/GSMime.h
@@ -75,9 +75,7 @@ extern "C" {
   NSMutableDictionary   *objects;
   NSMutableDictionary	*params;
 #endif
-#if	!GS_NONFRAGILE
-  void			*_unused;
-#endif
+  GS_PADDING_IVAR;
 }
 + (NSString*) makeQuoted: (NSString*)v always: (BOOL)flag;
 + (NSString*) makeToken: (NSString*)t preservingCase: (BOOL)preserve;
diff --git a/Headers/Additions/GNUstepBase/GSVersionMacros.h b/Headers/Additions/GNUstepBase/GSVersionMacros.h
index 8a10ff4ca..8fce6674b 100644
--- a/Headers/Additions/GNUstepBase/GSVersionMacros.h
+++ b/Headers/Additions/GNUstepBase/GSVersionMacros.h
@@ -228,6 +228,16 @@
 
 #define	GS_EXPOSE(X)	(!GS_NONFRAGILE || defined(EXPOSE_##X##_IVARS))
 
+#ifdef GS_NONFRAGILE
+#  define GS_PADDING_IVAR
+#else
+#  ifdef __clang__
+#    define GS_PADDING_IVAR __attribute__((unused)) void *gs_unused;
+#  else
+#    define GS_PADDING_IVAR void *gs_unused;
+#  endif
+#endif
+
 /* Include the appropriate header for ObjC2 blocks support if it is in use.
  *
  * FIXME: "OBJC2RUNTIME" is set to "1" if the runtime has
diff --git a/Headers/Foundation/NSArchiver.h b/Headers/Foundation/NSArchiver.h
index 7b66eea5e..c896bf097 100644
--- a/Headers/Foundation/NSArchiver.h
+++ b/Headers/Foundation/NSArchiver.h
@@ -70,9 +70,7 @@ extern "C" {
   BOOL		_encodingRoot;
   BOOL		_initialPass;
 #endif
-#if	!GS_NONFRAGILE
-  void		*_unused;
-#endif
+  GS_PADDING_IVAR;
 }
 
 /* Initializing an archiver */
@@ -178,9 +176,7 @@ extern "C" {
   NSMutableDictionary	*objDict;	/* Class information store.	*/
   NSMutableArray	*objSave;
 #endif
-#if	!GS_NONFRAGILE
-  void			*_unused;
-#endif
+  GS_PADDING_IVAR;
 }
 
 /* Initializing an unarchiver */
diff --git a/Headers/Foundation/NSAutoreleasePool.h b/Headers/Foundation/NSAutoreleasePool.h
index ec73a7d55..79f048d66 100644
--- a/Headers/Foundation/NSAutoreleasePool.h
+++ b/Headers/Foundation/NSAutoreleasePool.h
@@ -194,9 +194,7 @@ typedef struct autorelease_array_list
   /* The method to add an object to this pool */
   void 	(*_addImp)(id, SEL, id);
 #endif
-#if	!GS_NONFRAGILE
-  void	*_unused;
-#endif
+  GS_PADDING_IVAR;
 }
 
 /**
diff --git a/Headers/Foundation/NSBundle.h b/Headers/Foundation/NSBundle.h
index d93d4facc..3242b8754 100644
--- a/Headers/Foundation/NSBundle.h
+++ b/Headers/Foundation/NSBundle.h
@@ -119,9 +119,7 @@ GS_EXPORT NSString* const NSLoadedClasses;
   unsigned		_version;
   NSString      	*_frameworkVersion;
 #endif
-#if	!GS_NONFRAGILE
-  void			*_unused;
-#endif
+  GS_PADDING_IVAR;
 }
 
 /** Return an array enumerating all the bundles in the application.  This
diff --git a/Headers/Foundation/NSCache.h b/Headers/Foundation/NSCache.h
index 82e8f59b4..80edc80c9 100644
--- a/Headers/Foundation/NSCache.h
+++ b/Headers/Foundation/NSCache.h
@@ -61,9 +61,7 @@ extern "C" {
   /** Total number of accesses to objects */
   int64_t _totalAccesses;
 #endif
-#if	!GS_NONFRAGILE
-  void	*_unused;
-#endif
+  GS_PADDING_IVAR;
 }
 /** 
  * Returns the maximum number of objects that are supported by this cache.
diff --git a/Headers/Foundation/NSComparisonPredicate.h b/Headers/Foundation/NSComparisonPredicate.h
index 4163db48d..2d4f96ef9 100644
--- a/Headers/Foundation/NSComparisonPredicate.h
+++ b/Headers/Foundation/NSComparisonPredicate.h
@@ -77,9 +77,7 @@ typedef enum _NSPredicateOperatorType
   NSUInteger			_options;
   NSPredicateOperatorType	_type;
 #endif
-#if	!GS_NONFRAGILE
-  void				*_unused;
-#endif
+  GS_PADDING_IVAR;
   @public
   NSExpression			*_left;
   NSExpression			*_right;
diff --git a/Headers/Foundation/NSDateFormatter.h b/Headers/Foundation/NSDateFormatter.h
index 2dd892a9e..3ea487fe9 100644
--- a/Headers/Foundation/NSDateFormatter.h
+++ b/Headers/Foundation/NSDateFormatter.h
@@ -134,9 +134,7 @@ typedef NSUInteger NSDateFormatterBehavior;
   NSDateFormatterStyle _dateStyle;
   void      *_formatter;
 #endif
-#if	!GS_NONFRAGILE
-  void		*_unused;
-#endif
+  GS_PADDING_IVAR;
 }
 
 /* Initializing an NSDateFormatter */
diff --git a/Headers/Foundation/NSDecimalNumber.h b/Headers/Foundation/NSDecimalNumber.h
index b8ad88116..89d02a404 100644
--- a/Headers/Foundation/NSDecimalNumber.h
+++ b/Headers/Foundation/NSDecimalNumber.h
@@ -129,9 +129,7 @@ extern "C" {
   BOOL _raiseOnUnderflow;
   BOOL _raiseOnDivideByZero;
 #endif
-#if	!GS_NONFRAGILE
-  void	*_unused;
-#endif
+  GS_PADDING_IVAR;
 }
 
 /**
diff --git a/Headers/Foundation/NSDistributedLock.h b/Headers/Foundation/NSDistributedLock.h
index a455e2078..326def35f 100644
--- a/Headers/Foundation/NSDistributedLock.h
+++ b/Headers/Foundation/NSDistributedLock.h
@@ -40,9 +40,7 @@ extern "C" {
   NSString	*_lockPath;
   NSDate	*_lockTime;
 #endif
-#if	!GS_NONFRAGILE
-  void		*_unused;
-#endif
+  GS_PADDING_IVAR;
 }
 
 + (NSDistributedLock*) lockWithPath: (NSString*)aPath;
diff --git a/Headers/Foundation/NSDistributedNotificationCenter.h b/Headers/Foundation/NSDistributedNotificationCenter.h
index 87280ffe3..ab8ec2ba0 100644
--- a/Headers/Foundation/NSDistributedNotificationCenter.h
+++ b/Headers/Foundation/NSDistributedNotificationCenter.h
@@ -86,9 +86,7 @@ GS_EXPORT NSString* const GSNetworkNotificationCenterType;
   id		_remote;	/* Proxy for center.		*/
   BOOL		_suspended;	/* Is delivery suspended?	*/
 #endif
-#if	!GS_NONFRAGILE
-  void		*_unused;
-#endif
+  GS_PADDING_IVAR;
 }
 + (NSNotificationCenter*) defaultCenter;
 + (NSNotificationCenter*) notificationCenterForType: (NSString*)type;
diff --git a/Headers/Foundation/NSError.h b/Headers/Foundation/NSError.h
index a2a557eac..59c9e29ca 100644
--- a/Headers/Foundation/NSError.h
+++ b/Headers/Foundation/NSError.h
@@ -121,9 +121,7 @@ GS_EXPORT NSString* const NSCocoaErrorDomain;
   NSString	*_domain;
   NSDictionary	*_userInfo;
 #endif
-#if	!GS_NONFRAGILE
-  void		*_unused;
-#endif
+  GS_PADDING_IVAR;
 }
 
 /**
diff --git a/Headers/Foundation/NSFileHandle.h b/Headers/Foundation/NSFileHandle.h
index ed94ca424..2595571d1 100644
--- a/Headers/Foundation/NSFileHandle.h
+++ b/Headers/Foundation/NSFileHandle.h
@@ -162,9 +162,7 @@ GS_EXPORT NSString * const NSFileHandleOperationException;
   NSFileHandle	*_readHandle;
   NSFileHandle	*_writeHandle;
 #endif
-#if	!GS_NONFRAGILE
-  void		*_unused;
-#endif
+  GS_PADDING_IVAR;
 }
 + (id) pipe;
 - (NSFileHandle*) fileHandleForReading;
diff --git a/Headers/Foundation/NSFileManager.h b/Headers/Foundation/NSFileManager.h
index 42811fc1d..33c50f006 100644
--- a/Headers/Foundation/NSFileManager.h
+++ b/Headers/Foundation/NSFileManager.h
@@ -203,9 +203,7 @@ typedef	uint32_t	OSType;
 @private
   NSString	*_lastError;
 #endif
-#if	!GS_NONFRAGILE
-  void		*_unused;
-#endif
+  GS_PADDING_IVAR;
 }
 
 + (NSFileManager*) defaultManager;
@@ -389,9 +387,7 @@ typedef	uint32_t	OSType;
     BOOL justContents: 1;
   } _flags;
 #endif
-#if	!GS_NONFRAGILE
-  void	*_unused;
-#endif
+  GS_PADDING_IVAR;
 }
 - (NSDictionary*) directoryAttributes;
 - (NSDictionary*) fileAttributes;
diff --git a/Headers/Foundation/NSHost.h b/Headers/Foundation/NSHost.h
index bafcba093..7ed9da185 100644
--- a/Headers/Foundation/NSHost.h
+++ b/Headers/Foundation/NSHost.h
@@ -44,9 +44,7 @@ extern "C" {
   NSSet	*_names;
   NSSet	*_addresses;
 #endif
-#if	!GS_NONFRAGILE
-  void *_unused;
-#endif
+  GS_PADDING_IVAR;
 }
 
 /**
diff --git a/Headers/Foundation/NSIndexPath.h b/Headers/Foundation/NSIndexPath.h
index 64237d689..94d41e185 100644
--- a/Headers/Foundation/NSIndexPath.h
+++ b/Headers/Foundation/NSIndexPath.h
@@ -50,9 +50,7 @@ extern "C" {
   NSUInteger	_length;
   NSUInteger	*_indexes;
 #endif
-#if	!GS_NONFRAGILE
-  void		*_unused;
-#endif
+  GS_PADDING_IVAR;
 }
 
 /**
diff --git a/Headers/Foundation/NSInvocation.h b/Headers/Foundation/NSInvocation.h
index a7e4420e0..b96b57e3d 100644
--- a/Headers/Foundation/NSInvocation.h
+++ b/Headers/Foundation/NSInvocation.h
@@ -50,9 +50,7 @@ extern "C" {
   BOOL			_sendToSuper;
   void			*_retptr;
 #endif
-#if	!GS_NONFRAGILE
-  void			*_unused;
-#endif
+  GS_PADDING_IVAR;
 }
 
 /*
diff --git a/Headers/Foundation/NSKeyedArchiver.h b/Headers/Foundation/NSKeyedArchiver.h
index 9c076dbcf..0a05872dd 100644
--- a/Headers/Foundation/NSKeyedArchiver.h
+++ b/Headers/Foundation/NSKeyedArchiver.h
@@ -71,9 +71,7 @@ extern "C" {
   NSMutableArray	*_obj;	/* Array of objects.		*/
   NSPropertyListFormat	_format;
 #endif
-#if	!GS_NONFRAGILE
-  void			*_unused;
-#endif
+  GS_PADDING_IVAR;
 }
 
 /**
@@ -240,9 +238,7 @@ extern "C" {
 #endif
   NSZone	*_zone;		/* Zone for allocating objs.	*/
 #endif
-#if	!GS_NONFRAGILE
-  void		*_unused;
-#endif
+  GS_PADDING_IVAR;
 }
 
 /**
diff --git a/Headers/Foundation/NSLocale.h b/Headers/Foundation/NSLocale.h
index c27fb7641..ac8e55a5b 100644
--- a/Headers/Foundation/NSLocale.h
+++ b/Headers/Foundation/NSLocale.h
@@ -104,9 +104,7 @@ GS_EXPORT NSString * const NSISO8601Calendar;
   NSString		*_localeId;
   NSMutableDictionary	*_components;
 #endif
-#if	!GS_NONFRAGILE
-  void			*_unused;
-#endif
+  GS_PADDING_IVAR;
 }
 
 #if OS_API_VERSION(MAC_OS_X_VERSION_10_5, GS_API_LATEST)
diff --git a/Headers/Foundation/NSNumberFormatter.h b/Headers/Foundation/NSNumberFormatter.h
index 9c6161ece..102a1c2a1 100644
--- a/Headers/Foundation/NSNumberFormatter.h
+++ b/Headers/Foundation/NSNumberFormatter.h
@@ -145,9 +145,7 @@ typedef NSUInteger NSNumberFormatterRoundingMode;
   NSLocale  *_locale;
   void      *_formatter;
 #endif
-#if	!GS_NONFRAGILE
-  void		*_unused;
-#endif
+  GS_PADDING_IVAR;
 }
 
 // Format
diff --git a/Headers/Foundation/NSPort.h b/Headers/Foundation/NSPort.h
index d11c404a6..e0a4ce2b0 100644
--- a/Headers/Foundation/NSPort.h
+++ b/Headers/Foundation/NSPort.h
@@ -211,9 +211,7 @@ typedef SOCKET NSSocketNativeHandle;
   NSMapTable            *events;
 #endif
 #endif
-#if	!GS_NONFRAGILE
-  void			*_unused;
-#endif
+  GS_PADDING_IVAR;
 }
 
 /**
diff --git a/Headers/Foundation/NSPortCoder.h b/Headers/Foundation/NSPortCoder.h
index 32b40c2f4..9e705a40c 100644
--- a/Headers/Foundation/NSPortCoder.h
+++ b/Headers/Foundation/NSPortCoder.h
@@ -94,9 +94,7 @@ extern "C" {
   unsigned		_version;	/* Version of archiver used.	*/
   NSZone		*_zone;		/* Zone for allocating objs.	*/
 #endif
-#if	!GS_NONFRAGILE
-  void			*_unused;
-#endif
+  GS_PADDING_IVAR;
 }
 
 /**
diff --git a/Headers/Foundation/NSPortMessage.h b/Headers/Foundation/NSPortMessage.h
index 9d434cedd..72e5fdf69 100644
--- a/Headers/Foundation/NSPortMessage.h
+++ b/Headers/Foundation/NSPortMessage.h
@@ -51,9 +51,7 @@ extern "C" {
   NSPort		*_send;
   NSMutableArray	*_components;
 #endif
-#if	!GS_NONFRAGILE
-  void			*_unused;
-#endif
+  GS_PADDING_IVAR;
 }
 /**
  * OpenStep compatibility.
diff --git a/Headers/Foundation/NSPortNameServer.h b/Headers/Foundation/NSPortNameServer.h
index 1ad8ec8d5..9033f258f 100644
--- a/Headers/Foundation/NSPortNameServer.h
+++ b/Headers/Foundation/NSPortNameServer.h
@@ -60,9 +60,7 @@ extern "C" {
   NSMapTable	*_portMap;	/* Registered ports information.	*/
   NSMapTable	*_nameMap;	/* Registered names information.	*/
 #endif
-#if	!GS_NONFRAGILE
-  void		*_unused;
-#endif
+  GS_PADDING_IVAR;
 }
 + (id) sharedInstance;
 - (NSPort*) portForName: (NSString*)name
diff --git a/Headers/Foundation/NSProtocolChecker.h b/Headers/Foundation/NSProtocolChecker.h
index 2fa5d23cd..068d4eab2 100644
--- a/Headers/Foundation/NSProtocolChecker.h
+++ b/Headers/Foundation/NSProtocolChecker.h
@@ -42,9 +42,7 @@ extern "C" {
   Protocol *_myProtocol;
   NSObject *_myTarget;
 #endif
-#if	!GS_NONFRAGILE
-  void	*_unused;
-#endif
+  GS_PADDING_IVAR;
 }
 
 // Creating a checker
diff --git a/Headers/Foundation/NSRegularExpression.h b/Headers/Foundation/NSRegularExpression.h
index 025149e92..75b45780a 100644
--- a/Headers/Foundation/NSRegularExpression.h
+++ b/Headers/Foundation/NSRegularExpression.h
@@ -37,6 +37,7 @@ DEFINE_BLOCK_TYPE(GSRegexBlock, void, NSTextCheckingResult*, NSMatchingFlags, BO
 	@private
 	GSREGEXTYPE *regex;
 	NSRegularExpressionOptions options;
+	GS_PADDING_IVAR;
 }
 + (NSRegularExpression*)regularExpressionWithPattern: (NSString*)aPattern
                                              options: (NSRegularExpressionOptions)opts
diff --git a/Headers/Foundation/NSScanner.h b/Headers/Foundation/NSScanner.h
index b6d0454e2..569726d2e 100644
--- a/Headers/Foundation/NSScanner.h
+++ b/Headers/Foundation/NSScanner.h
@@ -50,9 +50,7 @@ extern "C" {
   BOOL			_caseSensitive;
   BOOL			_isUnicode;
 #endif
-#if	!GS_NONFRAGILE
-  void			*_unused;
-#endif
+  GS_PADDING_IVAR;
 }
 
 /*
diff --git a/Headers/Foundation/NSSortDescriptor.h b/Headers/Foundation/NSSortDescriptor.h
index 14f07dc03..a3bd91293 100644
--- a/Headers/Foundation/NSSortDescriptor.h
+++ b/Headers/Foundation/NSSortDescriptor.h
@@ -50,9 +50,7 @@ extern "C" {
   BOOL	_ascending;
   SEL	_selector;
 #endif
-#if	!GS_NONFRAGILE
-  void	*_unused;
-#endif
+  GS_PADDING_IVAR;
 }
 
 /** Returns a flag indicating whether the sort descriptor sorts objects
diff --git a/Headers/Foundation/NSTask.h b/Headers/Foundation/NSTask.h
index 56c76eec0..834d43e19 100644
--- a/Headers/Foundation/NSTask.h
+++ b/Headers/Foundation/NSTask.h
@@ -54,9 +54,7 @@ extern "C" {
   BOOL		_hasCollected;
   BOOL		_hasNotified;
 #endif
-#if	!GS_NONFRAGILE
-  void		*_unused;
-#endif
+  GS_PADDING_IVAR;
 }
 
 + (NSTask*) launchedTaskWithLaunchPath: (NSString*)path
diff --git a/Headers/Foundation/NSThread.h b/Headers/Foundation/NSThread.h
index e40c3d29f..ba6dbe974 100644
--- a/Headers/Foundation/NSThread.h
+++ b/Headers/Foundation/NSThread.h
@@ -72,9 +72,7 @@ extern "C" {
   id			_gcontext;
   void                  *_runLoopInfo;  // Per-thread runloop related info.
 #endif
-#if	!GS_NONFRAGILE
-  void                  *_unused;     // For future expansion
-#endif
+  GS_PADDING_IVAR;
 }
 
 /**
diff --git a/Headers/Foundation/NSTimer.h b/Headers/Foundation/NSTimer.h
index 80ecae838..22273d950 100644
--- a/Headers/Foundation/NSTimer.h
+++ b/Headers/Foundation/NSTimer.h
@@ -51,9 +51,7 @@ extern "C" {
   SEL		_selector;
   id		_info;
 #endif
-#if	!GS_NONFRAGILE
-  void		*_unused;
-#endif
+  GS_PADDING_IVAR;
 }
 
 /* Creating timer objects. */
diff --git a/Headers/Foundation/NSUndoManager.h b/Headers/Foundation/NSUndoManager.h
index 81ec14eb7..488fb9f6f 100644
--- a/Headers/Foundation/NSUndoManager.h
+++ b/Headers/Foundation/NSUndoManager.h
@@ -98,9 +98,7 @@ GS_EXPORT NSString* const NSUndoManagerWillUndoChangeNotification;
   unsigned		_disableCount;
   unsigned		_levelsOfUndo;
 #endif
-#if	!GS_NONFRAGILE
-  void			*_unused;
-#endif
+  GS_PADDING_IVAR;
 }
 
 - (void) beginUndoGrouping;
diff --git a/Headers/Foundation/NSUserDefaults.h b/Headers/Foundation/NSUserDefaults.h
index 09fa2ee72..c7f4aa736 100644
--- a/Headers/Foundation/NSUserDefaults.h
+++ b/Headers/Foundation/NSUserDefaults.h
@@ -228,9 +228,7 @@ GS_EXPORT NSString* const GSLocale;
   NSRecursiveLock	*_lock;
   NSDistributedLock	*_fileLock;
 #endif
-#if	!GS_NONFRAGILE
-  void			*_unused;
-#endif
+  GS_PADDING_IVAR;
 }
 
 /**
diff --git a/Headers/Foundation/NSXMLNode.h b/Headers/Foundation/NSXMLNode.h
index 279363212..fbd7bf7e6 100644
--- a/Headers/Foundation/NSXMLNode.h
+++ b/Headers/Foundation/NSXMLNode.h
@@ -88,9 +88,7 @@ typedef NSUInteger NSXMLNodeKind;
   NSUInteger    _index;
   id            _objectValue;
 #endif
-#if	!GS_NONFRAGILE
-  void		*_unused;
-#endif
+  GS_PADDING_IVAR;
 }
 
 /**
diff --git a/Headers/Foundation/NSXMLParser.h b/Headers/Foundation/NSXMLParser.h
index 284f84899..fd679a1f6 100644
--- a/Headers/Foundation/NSXMLParser.h
+++ b/Headers/Foundation/NSXMLParser.h
@@ -74,9 +74,7 @@ GS_EXPORT NSString* const NSXMLParserErrorDomain;
   void		*_parser;	// GSXMLParser
   void		*_handler;	// SAXHandler
 #endif
-#if	!GS_NONFRAGILE
-  void		*_unused;
-#endif
+  GS_PADDING_IVAR;
 }
 
 /**