diff --git a/libavcodec/me_cmp.c b/libavcodec/me_cmp.c
index 09a830d15e..2a8ede5955 100644
--- a/libavcodec/me_cmp.c
+++ b/libavcodec/me_cmp.c
@@ -758,7 +758,7 @@ static int rd8x8_c(MPVEncContext *const s, const uint8_t *src1, const uint8_t *s
     LOCAL_ALIGNED_16(uint8_t, lsrc2, [64]);
     int i, last, run, bits, level, distortion, start_i;
     const int esc_length = s->ac_esc_length;
-    uint8_t *length, *last_length;
+    const uint8_t *length, *last_length;
 
     copy_block8(lsrc1, src1, 8, stride, 8);
     copy_block8(lsrc2, src2, 8, stride, 8);
@@ -831,7 +831,7 @@ static int bit8x8_c(MPVEncContext *const s, const uint8_t *src1, const uint8_t *
     LOCAL_ALIGNED_16(int16_t, temp, [64]);
     int i, last, run, bits, level, start_i;
     const int esc_length = s->ac_esc_length;
-    uint8_t *length, *last_length;
+    const uint8_t *length, *last_length;
 
     s->pdsp.diff_pixels_unaligned(temp, src1, src2, stride);
 
diff --git a/libavcodec/mpegvideoenc.h b/libavcodec/mpegvideoenc.h
index 689297e55c..6e76185c0c 100644
--- a/libavcodec/mpegvideoenc.h
+++ b/libavcodec/mpegvideoenc.h
@@ -93,13 +93,13 @@ typedef struct MPVEncContext {
     int min_qcoeff;          ///< minimum encodable coefficient
     int max_qcoeff;          ///< maximum encodable coefficient
     int ac_esc_length;       ///< num of bits needed to encode the longest esc
-    uint8_t *intra_ac_vlc_length;
-    uint8_t *intra_ac_vlc_last_length;
-    uint8_t *intra_chroma_ac_vlc_length;
-    uint8_t *intra_chroma_ac_vlc_last_length;
-    uint8_t *inter_ac_vlc_length;
-    uint8_t *inter_ac_vlc_last_length;
-    uint8_t *luma_dc_vlc_length;
+    const uint8_t *intra_ac_vlc_length;
+    const uint8_t *intra_ac_vlc_last_length;
+    const uint8_t *intra_chroma_ac_vlc_length;
+    const uint8_t *intra_chroma_ac_vlc_last_length;
+    const uint8_t *inter_ac_vlc_length;
+    const uint8_t *inter_ac_vlc_last_length;
+    const uint8_t *luma_dc_vlc_length;
 
     int coded_score[12];