diff --git a/libavcodec/wmalosslessdec.c b/libavcodec/wmalosslessdec.c
index 22596bd5f8..8eb473e3ba 100644
--- a/libavcodec/wmalosslessdec.c
+++ b/libavcodec/wmalosslessdec.c
@@ -793,8 +793,8 @@ static void revert_inter_ch_decorr(WmallDecodeCtx *s, int tile_size)
     else if (s->is_channel_coded[0] || s->is_channel_coded[1]) {
         int icoef;
         for (icoef = 0; icoef < tile_size; icoef++) {
-            s->channel_residues[0][icoef] -= s->channel_residues[1][icoef] >> 1;
-            s->channel_residues[1][icoef] += s->channel_residues[0][icoef];
+            s->channel_residues[0][icoef] -= (unsigned)(s->channel_residues[1][icoef] >> 1);
+            s->channel_residues[1][icoef] += (unsigned) s->channel_residues[0][icoef];
         }
     }
 }