diff --git a/libavcodec/h263dec.c b/libavcodec/h263dec.c
index 31580e4dbf..78e13300b9 100644
--- a/libavcodec/h263dec.c
+++ b/libavcodec/h263dec.c
@@ -623,11 +623,14 @@ retry:
     fprintf(f, "%d %d %f\n", buf_size, s->qscale, buf_size*(double)s->qscale);
 }
 #endif
-    
+
+#ifdef HAVE_MMX
     if(s->codec_id == CODEC_ID_MPEG4 && s->xvid_build && avctx->idct_algo == FF_IDCT_AUTO && (mm_flags & MM_MMX) && !(s->flags&CODEC_FLAG_BITEXACT)){
         avctx->idct_algo= FF_IDCT_LIBMPEG2MMX;
         avctx->width= 0; // force reinit
     }
+#endif
+
         /* After H263 & mpeg4 header decode we have the height, width,*/
         /* and other parameters. So then we could init the picture   */
         /* FIXME: By the way H263 decoder is evolving it should have */