diff --git a/libavcodec/ac3dec.c b/libavcodec/ac3dec.c
index b6ee4014852db580aba6357c29b6ce43b797ceaf..2cceadc8781a2b7fdbfde21c3312dbd2bf2da421 100644
--- a/libavcodec/ac3dec.c
+++ b/libavcodec/ac3dec.c
@@ -237,9 +237,9 @@ static int ac3_parse_header(AC3DecodeContext *s)
         if (get_bits1(gbc)) {
             s->preferred_downmix       = get_bits(gbc, 2);
             s->center_mix_level_ltrt   = get_bits(gbc, 3);
-            s->surround_mix_level_ltrt = get_bits(gbc, 3);
+            s->surround_mix_level_ltrt = av_clip(get_bits(gbc, 3), 3, 7);
             s->center_mix_level        = get_bits(gbc, 3);
-            s->surround_mix_level      = get_bits(gbc, 3);
+            s->surround_mix_level      = av_clip(get_bits(gbc, 3), 3, 7);
         }
         if (get_bits1(gbc)) {
             s->dolby_surround_ex_mode = get_bits(gbc, 2);
diff --git a/libavcodec/eac3dec.c b/libavcodec/eac3dec.c
index dfd78c6ad717ce61a0e7339bc532dddfd8511e1c..95ee33f823353ace8a400c28598ac796854be6a0 100644
--- a/libavcodec/eac3dec.c
+++ b/libavcodec/eac3dec.c
@@ -353,8 +353,8 @@ int ff_eac3_parse_header(AC3DecodeContext *s)
             }
             if (s->channel_mode & 4) {
                 /* if a surround channel exists */
-                s->surround_mix_level_ltrt = get_bits(gbc, 3);
-                s->surround_mix_level = get_bits(gbc, 3);
+                s->surround_mix_level_ltrt = av_clip(get_bits(gbc, 3), 3, 7);
+                s->surround_mix_level = av_clip(get_bits(gbc, 3), 3, 7);
             }
         }