diff --git a/mfhdf/xdr/xdr.c b/mfhdf/xdr/xdr.c
index 616d5920..19bec832 100644
--- a/mfhdf/xdr/xdr.c
+++ b/mfhdf/xdr/xdr.c
@@ -549,3 +549,34 @@ xdr_wrapstring(xdrs, cpp)
 	}
 	return (FALSE);
 }
+
+bool_t
+xdr_hyper (XDR *xdrs, quad_t *llp)
+{
+  long int t1, t2;
+
+    printf("xdr_hyper...\n");
+  if (xdrs->x_op == XDR_ENCODE)
+    {
+      t1 = (long) ((*llp) >> 32);
+      t2 = (long) (*llp);
+      return (XDR_PUTLONG(xdrs, &t1) && XDR_PUTLONG(xdrs, &t2));
+    }
+
+  if (xdrs->x_op == XDR_DECODE)
+    {
+      if (!XDR_GETLONG(xdrs, &t1) || !XDR_GETLONG(xdrs, &t2))
+    return FALSE;
+        printf("t1 = %ld, t2 = %ld\n", t1, t2);
+      *llp = ((quad_t) t1) << 32;
+      *llp |= (uint32_t) t2;
+      return TRUE;
+    }
+
+  if (xdrs->x_op == XDR_FREE)
+    return TRUE;
+
+  return FALSE;
+}
+
+
diff --git a/mfhdf/xdr/xdr.h b/mfhdf/xdr/xdr.h
index 2ee293dc..08c54b24 100644
--- a/mfhdf/xdr/xdr.h
+++ b/mfhdf/xdr/xdr.h
@@ -50,6 +50,7 @@ enum xdr_op {
 	XDR_FREE=2
 };
 
+typedef long long quad_t; 
 /*
  * This is the number of bytes per unit of external data.
  */
@@ -202,6 +203,7 @@ XDRLIBAPI bool_t	xdr_int(XDR *, int *);
 XDRLIBAPI bool_t	xdr_u_int(XDR *, u_int *);
 XDRLIBAPI bool_t	xdr_long(XDR *, long *);
 XDRLIBAPI bool_t	xdr_u_long(XDR *, u_long *);
+XDRLIBAPI bool_t	xdr_hyper(XDR *, quad_t *);
 XDRLIBAPI bool_t	xdr_short(XDR *, short *);
 XDRLIBAPI bool_t	xdr_u_short(XDR *, u_short *);
 XDRLIBAPI bool_t	xdr_bool(XDR *, bool_t *);
diff --git a/mfhdf/xdr/xdrtest.c b/mfhdf/xdr/xdrtest.c
index 1a393cfc..07323195 100644
--- a/mfhdf/xdr/xdrtest.c
+++ b/mfhdf/xdr/xdrtest.c
@@ -105,8 +105,8 @@ char *av[] ;
 
 	long lnum = 82555 ;
 
-	static long longs[5] = { -4, -3, -2, -1, 0} ;
-	long *lp , got_al[5] ;
+	static long long longs[5] = { -4, -3, -2, -1, 0} ;
+	quad_t *lp , got_al[5] ;
 
 	static unsigned long u_longs[5] = {
 		((unsigned)65535),
@@ -187,7 +187,7 @@ char *av[] ;
 	assert( xdr_setpos(xdrs, seeks[jj])) ;
 	szof = sizeof(long) ;
 	count = sizeof(longs)/sizeof(long) ;
-	assert( xdr_vector(xdrs, (char *)longs, count, szof, xdr_long)) ;
+	assert( xdr_vector(xdrs, (char *)longs, count, szof, xdr_hyper)) ;
 	poses[jj++] = xdr_getpos(xdrs) ;
 
 	assert( xdr_setpos(xdrs, seeks[jj])) ;
@@ -296,7 +296,8 @@ char *av[] ;
 	assert( xdr_setpos(xdrs, seeks[jj])) ;
 	szof = sizeof(long) ;
 	count = sizeof(longs)/sizeof(long) ;
-	assert( xdr_vector(xdrs, (char *)got_al, count, szof, xdr_long)) ;
+
+	assert( xdr_vector(xdrs, (char *)got_al, count, szof, xdr_hyper)) ;
 	assert( poses[jj++] = xdr_getpos(xdrs) ) ;
 	printf("longs: ");
 	for(ii = 0, lp = got_al ;