@@ -56,10 +56,11 @@
 # include <stdbool.h>
 # include <filesystem.h>
 #endif
 
 #ifdef OF_AMIGAOS
+# define __USE_INLINE__
 # include <proto/dos.h>
 #endif
 
 #ifndef O_BINARY
 # define O_BINARY 0
@@ -272,13 +273,16 @@
 						 mode: mode
 						errNo: errNo];
 			}
 
 			if (handle->append) {
-# ifdef OF_MORPHOS
+# if defined(OF_MORPHOS)
 				if (Seek64(handle->handle, 0,
 				    OFFSET_END) == -1) {
+# elif defined(OF_AMIGAOS4)
+				if (ChangeFilePosition(handle->handle, 0,
+				    OFFSET_END) == -1) {
 # else
 				if (Seek(handle->handle, 0, OFFSET_END) == -1) {
 # endif
 					Close(handle->handle);
 					@throw [OFOpenItemFailedException
@@ -414,12 +418,14 @@
 
 	if (length > LONG_MAX)
 		@throw [OFOutOfRangeException exception];
 
 	if (_handle->append) {
-# ifdef OF_MORPHOS
+# if defined(OF_MORPHOS)
 		if (Seek64(_handle->handle, 0, OFFSET_END) == -1)
+# elif defined(OF_AMIGAOS4)
+		if (ChangeFilePosition(_handle->handle, 0, OFFSET_END) == -1)
 # else
 		if (Seek(_handle->handle, 0, OFFSET_END) == -1)
 # endif
 			@throw [OFWriteFailedException
 			    exceptionWithObject: self
@@ -489,12 +495,15 @@
 							   offset: offset
 							   whence: whence
 							    errNo: EINVAL];
 	}
 
-# ifdef OF_MORPHOS
+# if defined(OF_MORPHOS)
 	if ((ret = Seek64(_handle->handle, offset, translatedWhence)) == 1)
+# elif defined(OF_AMIGAOS4)
+	if ((ret = ChangeFilePosition(_handle->handle, offset,
+	    translatedWhence)) == 1)
 # else
 	if ((ret = Seek(_handle->handle, offset, translatedWhence)) == 1)
 # endif
 		@throw [OFSeekFailedException exceptionWithStream: self
 							   offset: offset