Index: fuse_io.c
===================================================================
--- fuse_io.c	(revision 244484)
+++ fuse_io.c	(working copy)
@@ -113,7 +113,7 @@
     struct ucred *cred, struct fuse_filehandle *fufh);
 static int 
 fuse_write_biobackend(struct vnode *vp, struct uio *uio,
-    struct ucred *cred, struct fuse_filehandle *fufh);
+    struct ucred *cred, struct fuse_filehandle *fufh, int ioflag);
 
 int
 fuse_io_dispatch(struct vnode *vp, struct uio *uio, int ioflag,
@@ -162,7 +162,7 @@
 		} else {
 			FS_DEBUG("buffered write of vnode %ju\n", 
 			      (uintmax_t)VTOILLU(vp));
-			err = fuse_write_biobackend(vp, uio, cred, fufh);
+			err = fuse_write_biobackend(vp, uio, cred, fufh, ioflag);
 		}
 		break;
 	default:
@@ -371,7 +371,7 @@
 
 static int
 fuse_write_biobackend(struct vnode *vp, struct uio *uio,
-    struct ucred *cred, struct fuse_filehandle *fufh)
+    struct ucred *cred, struct fuse_filehandle *fufh, int ioflag)
 {
 	struct fuse_vnode_data *fvdat = VTOFUD(vp);
 	struct buf *bp;
@@ -390,6 +390,8 @@
 		return (EINVAL);
 	if (uio->uio_resid == 0)
 		return (0);
+	if (ioflag & IO_APPEND)
+		uio_setoffset(uio, fvdat->filesize);
 
 	/*
          * Find all of this file's B_NEEDCOMMIT buffers.  If our writes