diff --git a/libavcodec/ra288.c b/libavcodec/ra288.c
index 5fb41bf4e9..7702a3c350 100644
--- a/libavcodec/ra288.c
+++ b/libavcodec/ra288.c
@@ -69,13 +69,12 @@ static void decode(Real288_internal *glob, float gain, int cb_coef)
 
     sumsum = exp(sum * 0.1151292546497) * gain;    /* pow(10.0,sum/20)*f */
 
-    sum = 0;
     for (x=0; x < 5; x++) {
         buffer[x] = codetable[cb_coef][x] * sumsum;
-        sum += buffer[x] * buffer[x];
     }
 
-    sum /= 5;
+    sum = scalar_product_float(buffer, buffer, 5) / 5;
+
     if (sum < 1)
         sum = 1;