diff --git a/libavcodec/truespeech.c b/libavcodec/truespeech.c
index 7747fca6b2..b7a2aa6fba 100644
--- a/libavcodec/truespeech.c
+++ b/libavcodec/truespeech.c
@@ -233,8 +233,7 @@ static void truespeech_update_filters(TSContext *dec, int16_t *out, int quart)
 {
     int i;
 
-    for(i = 0; i < 86; i++)
-        dec->filtbuf[i] = dec->filtbuf[i + 60];
+    memmove(dec->filtbuf, &dec->filtbuf[60], 86 * sizeof(*dec->filtbuf));
     for(i = 0; i < 60; i++){
         dec->filtbuf[i + 86] = out[i] + dec->newvec[i] - (dec->newvec[i] >> 3);
         out[i] += dec->newvec[i];