diff --git a/libavcodec/faxcompr.c b/libavcodec/faxcompr.c
index bb18abf0a7..10a0730417 100644
--- a/libavcodec/faxcompr.c
+++ b/libavcodec/faxcompr.c
@@ -131,12 +131,12 @@ static int decode_group3_1d_line(AVCodecContext *avctx, GetBitContext *gb,
         t = get_vlc2(gb, ccitt_vlc[mode].table, 9, 2);
         run += t;
         if(t < 64){
-            pix_left -= run;
             *runs++ = run;
             if(runs >= runend){
                 av_log(avctx, AV_LOG_ERROR, "Run overrun\n");
                 return -1;
             }
+            pix_left -= run;
             if(pix_left <= 0){
                 if(!pix_left)
                     break;