diff --git a/libavcodec/faxcompr.c b/libavcodec/faxcompr.c
index 0853ed4af6..f8a8b93841 100644
--- a/libavcodec/faxcompr.c
+++ b/libavcodec/faxcompr.c
@@ -136,7 +136,7 @@ static int decode_group3_1d_line(AVCodecContext *avctx, GetBitContext *gb,
             if(pix_left <= 0){
                 if(!pix_left)
                     break;
-                runs[-1] = 0;
+                runs[-1] += pix_left;
                 av_log(avctx, AV_LOG_ERROR, "Run went out of bounds\n");
                 return -1;
             }