diff --git a/src/modules/audio_conference_mixer/source/level_indicator.cc b/src/modules/audio_conference_mixer/source/level_indicator.cc
index 9e9133eda..799a47ddd 100644
--- a/src/modules/audio_conference_mixer/source/level_indicator.cc
+++ b/src/modules/audio_conference_mixer/source/level_indicator.cc
@@ -12,7 +12,7 @@
 
 namespace webrtc {
 // Array for adding smothing to level changes (ad-hoc).
-WebRtc_UWord32 perm[] =
+const WebRtc_UWord32 perm[] =
     {0,1,2,3,4,4,5,5,5,5,6,6,6,6,6,7,7,7,7,8,8,8,9,9,9,9,9,9,9,9,9,9,9};
 
 LevelIndicator::LevelIndicator()