diff --git a/libavcodec/dxva2_h264.c b/libavcodec/dxva2_h264.c
index 03af474892..093db99ec3 100644
--- a/libavcodec/dxva2_h264.c
+++ b/libavcodec/dxva2_h264.c
@@ -222,7 +222,7 @@ static void fill_slice_long(AVCodecContext *avctx, DXVA_Slice_H264_Long *slice,
 
     slice->first_mb_in_slice     = (sl->mb_y >> FIELD_OR_MBAFF_PICTURE(h)) * h->mb_width + sl->mb_x;
     slice->NumMbsForSlice        = 0; /* XXX it is set once we have all slices */
-    slice->BitOffsetToSliceData  = get_bits_count(&h->gb);
+    slice->BitOffsetToSliceData  = get_bits_count(&sl->gb);
     slice->slice_type            = ff_h264_get_slice_type(sl);
     if (sl->slice_type_fixed)
         slice->slice_type += 5;