diff --git a/ChangeLog b/ChangeLog
index fe41a39fa..5da69d7f4 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,13 @@
+2003-04-09  Richard Frith-Macdonald <rfm@gnu.org>
+
+	* Source/GSTcpPort.m:
+	* Source/NSData.m:
+	* Source/NSSerializer.m:
+	* Source/NSURL.m:
+	Replace __alignof__() with calls to objc_alignof_type() so that if
+	__alignof__() is broken we can hope that the objc runtime library
+	has a workaround.
+
 2003-04-08  Richard Frith-Macdonald <rfm@gnu.org>
 
 	* Headers/gnustep/base/Foundation.h: Include GNUstep extensions
diff --git a/Source/GSTcpPort.m b/Source/GSTcpPort.m
index fa01b69f9..f54fc431e 100644
--- a/Source/GSTcpPort.m
+++ b/Source/GSTcpPort.m
@@ -1348,10 +1348,17 @@ static Class		tcpPortClass;
 	    object: nil];
 }
 
+#if NEED_WORD_ALIGNMENT
+static unsigned	wordAlign;
+#endif
+
 + (void) initialize
 {
   if (self == [GSTcpPort class])
     {
+#if NEED_WORD_ALIGNMENT
+      wordAlign = objc_alignof_type(@encode(gsu32));
+#endif
       tcpPortClass = self;
       tcpPortMap = NSCreateMapTable(NSIntMapKeyCallBacks,
 	NSNonOwnedPointerMapValueCallBacks, 0);
@@ -2117,7 +2124,7 @@ static Class		tcpPortClass;
 		   * word boundary, so we work with an aligned buffer
 		   * and use memcmpy()
 		   */
-		  if ((hLength % __alignof__(gsu32)) != 0)
+		  if ((hLength % wordAlign) != 0)
 		    {
 		      GSPortItemHeader	itemHeader;
 
diff --git a/Source/NSData.m b/Source/NSData.m
index 067812652..3676799a9 100644
--- a/Source/NSData.m
+++ b/Source/NSData.m
@@ -378,10 +378,19 @@ failure:
 
 @implementation NSData
 
+#if NEED_WORD_ALIGNMENT
+static unsigned	gsu16Align;
+static unsigned	gsu32Align;
+#endif
+
 + (void) initialize
 {
   if (self == [NSData class])
     {
+#if NEED_WORD_ALIGNMENT
+      gsu16Align = objc_alignof_type(@encode(gsu16));
+      gsu32Align = objc_alignof_type(@encode(gsu32));
+#endif
       NSDataAbstract = self;
       NSMutableDataAbstract = [NSMutableData class];
       dataMalloc = [NSDataMalloc class];
@@ -2615,7 +2624,7 @@ getBytes(void* dst, void* src, unsigned len, unsigned limit, unsigned *pos)
 			  *cursor, length];
 		}
 #if NEED_WORD_ALIGNMENT
-	      if ((*cursor % __alignof__(gsu16)) != 0)
+	      if ((*cursor % gsu16Align) != 0)
 		memcpy(&x, (bytes + *cursor), 2);
 	      else
 #endif
@@ -2635,7 +2644,7 @@ getBytes(void* dst, void* src, unsigned len, unsigned limit, unsigned *pos)
 			  *cursor, length];
 		}
 #if NEED_WORD_ALIGNMENT
-	      if ((*cursor % __alignof__(gsu32)) != 0)
+	      if ((*cursor % gsu32Align) != 0)
 		memcpy(&x, (bytes + *cursor), 4);
 	      else
 #endif
@@ -3345,7 +3354,7 @@ getBytes(void* dst, void* src, unsigned len, unsigned limit, unsigned *pos)
 	}
       *(gsu8*)(bytes + length++) = tag;
 #if NEED_WORD_ALIGNMENT
-      if ((length % __alignof__(gsu16)) != 0)
+      if ((length % gsu16Align) != 0)
 	{
 	  x = GSSwapHostI16ToBig(x);
 	  memcpy((bytes + length), &x, 2);
@@ -3366,7 +3375,7 @@ getBytes(void* dst, void* src, unsigned len, unsigned limit, unsigned *pos)
 	}
       *(gsu8*)(bytes + length++) = tag;
 #if NEED_WORD_ALIGNMENT
-      if ((length % __alignof__(gsu32)) != 0)
+      if ((length % gsu32Align) != 0)
 	{
 	  x = GSSwapHostI32ToBig(x);
 	  memcpy((bytes + length), &x, 4);
diff --git a/Source/NSSerializer.m b/Source/NSSerializer.m
index 76b444612..932c82ae1 100644
--- a/Source/NSSerializer.m
+++ b/Source/NSSerializer.m
@@ -113,6 +113,10 @@ static Class	MStringClass = 0;
 static Class	StringClass = 0;
 static Class	NumberClass = 0;
 
+#if NEED_WORD_ALIGNMENT
+static unsigned	gsu32Align;
+#endif
+
 typedef struct {
   @defs(GSString)
 } *ivars;
@@ -229,7 +233,7 @@ serializeToInfo(id object, _NSSerializerInfo* info)
 	   * word boundary, so we work with an aligned buffer
 	   * and use memcmpy()
 	   */
- 	  if ((dlen % __alignof__(gsu32)) != 0)
+ 	  if ((dlen % gsu32Align) != 0)
 	    {
 	      unichar buffer[slen];
 	      [object getCharacters: buffer];
@@ -339,6 +343,9 @@ static BOOL	shouldBeCompact = NO;
 {
   if (self == [NSSerializer class])
     {
+#if NEED_WORD_ALIGNMENT
+      gsu32Align = objc_alignof_type(@encode(gsu32));
+#endif
       appSel = @selector(appendBytes:length:);
       datSel = @selector(mutableBytes);
       lenSel = @selector(length);
diff --git a/Source/NSURL.m b/Source/NSURL.m
index c6138d5fa..dede21197 100644
--- a/Source/NSURL.m
+++ b/Source/NSURL.m
@@ -472,6 +472,8 @@ static void unescape(const char *from, char * to)
  */
 @implementation NSURL
 
+static unsigned	urlAlign;
+
 /**
  * Create and return a file URL with the supplied path.<br />
  * The value of aPath must be a valid filesystem path.<br />
@@ -486,6 +488,7 @@ static void unescape(const char *from, char * to)
 {
   if (clientsLock == nil)
     {
+      urlAlign = objc_alignof_type(@encode(parsedURL));
       clientsLock = [NSLock new];
     }
 }
@@ -637,7 +640,7 @@ static void unescape(const char *from, char * to)
       BOOL	usesQueries = YES;
       BOOL	canBeGeneric = YES;
 
-      size += sizeof(parsedURL) + __alignof__(parsedURL) + 1;
+      size += sizeof(parsedURL) + urlAlign + 1;
       buf = _data = (parsedURL*)NSZoneMalloc(GSAtomicMallocZone(), size);
       memset(buf, '\0', size);
       start = end = ptr = (char*)&buf[1];