diff --git a/libavcodec/faxcompr.c b/libavcodec/faxcompr.c
index ad99a64a58..e7f7706b94 100644
--- a/libavcodec/faxcompr.c
+++ b/libavcodec/faxcompr.c
@@ -212,7 +212,7 @@ static int decode_group3_2d_line(AVCodecContext *avctx, GetBitContext *gb,
             return -1;
         }else{//vertical mode
             run = run_off - offs + (cmode - 5);
-                run_off -= *--ref;
+            run_off -= *--ref;
             offs += run;
             if(offs > width || run > width){
                 av_log(avctx, AV_LOG_ERROR, "Run went out of bounds\n");