diff --git a/modules/audio_coding/codecs/isac/main/source/entropy_coding.c b/modules/audio_coding/codecs/isac/main/source/entropy_coding.c
index 28767afc63..6692a519ca 100644
--- a/modules/audio_coding/codecs/isac/main/source/entropy_coding.c
+++ b/modules/audio_coding/codecs/isac/main/source/entropy_coding.c
@@ -96,7 +96,7 @@ static void FindInvArSpec(const int16_t* ARCoefQ12,
                           const int32_t gainQ10,
                           int32_t* CurveQ16) {
   int32_t CorrQ11[AR_ORDER + 1];
-  int32_t sum, tmpGain;
+  int64_t sum, tmpGain;
   int32_t diffQ16[FRAMESAMPLES / 8];
   const int16_t* CS_ptrQ9;
   int k, n;