diff --git a/libavcodec/ppc/mpegvideo_altivec.c b/libavcodec/ppc/mpegvideo_altivec.c
index 51b387792c..91e744af97 100644
--- a/libavcodec/ppc/mpegvideo_altivec.c
+++ b/libavcodec/ppc/mpegvideo_altivec.c
@@ -1,6 +1,9 @@
 /*
  * Copyright (c) 2002 Dieter Shirley
  *
+ * dct_unquantize_h263_altivec:
+ * Copyright (c) 2003 Romain Dolbeau <romain@dolbeau.org>
+ *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
diff --git a/libavcodec/ppc/mpegvideo_ppc.c b/libavcodec/ppc/mpegvideo_ppc.c
index 54e6f35c2a..c8269eb9a3 100644
--- a/libavcodec/ppc/mpegvideo_ppc.c
+++ b/libavcodec/ppc/mpegvideo_ppc.c
@@ -71,7 +71,9 @@ void MPV_common_init_ppc(MpegEncContext *s)
         if ((s->avctx->dct_algo == FF_DCT_AUTO) ||
                 (s->avctx->dct_algo == FF_DCT_ALTIVEC))
         {
+#if 0 /* seems to cause trouble under some circumstances */
             s->dct_quantize = dct_quantize_altivec;
+#endif
             s->dct_unquantize_h263_intra = dct_unquantize_h263_altivec;
             s->dct_unquantize_h263_inter = dct_unquantize_h263_altivec;
         }