diff --git a/libavcodec/magicyuv.c b/libavcodec/magicyuv.c
index ae1660eaa3..65dbb6a2f1 100644
--- a/libavcodec/magicyuv.c
+++ b/libavcodec/magicyuv.c
@@ -115,7 +115,7 @@ static void magicyuv_median_pred16(uint16_t *dst, const uint16_t *src1,
 static int magy_decode_slice10(AVCodecContext *avctx, void *tdata,
                                int j, int threadnr)
 {
-    MagicYUVContext *s = avctx->priv_data;
+    const MagicYUVContext *s = avctx->priv_data;
     int interlaced = s->interlaced;
     const int bps = s->bps;
     const int max = s->max - 1;
@@ -247,7 +247,7 @@ static int magy_decode_slice10(AVCodecContext *avctx, void *tdata,
 static int magy_decode_slice(AVCodecContext *avctx, void *tdata,
                              int j, int threadnr)
 {
-    MagicYUVContext *s = avctx->priv_data;
+    const MagicYUVContext *s = avctx->priv_data;
     int interlaced = s->interlaced;
     AVFrame *p = s->p;
     int i, k, x, min_width;