diff --git a/3rdparty/iaxclient/lib/spandsp/plc.c b/3rdparty/iaxclient/lib/spandsp/plc.c
index 4edbb2dc5..4efd4183e 100644
--- a/3rdparty/iaxclient/lib/spandsp/plc.c
+++ b/3rdparty/iaxclient/lib/spandsp/plc.c
@@ -107,7 +107,9 @@ static void normalise_history(plc_state_t *s)
     if (s->buf_ptr == 0)
         return;
     memcpy(tmp, s->history, sizeof(int16_t)*s->buf_ptr);
-    memcpy(s->history, s->history + s->buf_ptr, sizeof(int16_t)*(PLC_HISTORY_LEN - s->buf_ptr));
+    
+    // FlightGear fix: use memove, becuase ASan reports overlaps here
+    memmove(s->history, s->history + s->buf_ptr, sizeof(int16_t)*(PLC_HISTORY_LEN - s->buf_ptr));
     memcpy(s->history + PLC_HISTORY_LEN - s->buf_ptr, tmp, sizeof(int16_t)*s->buf_ptr);
     s->buf_ptr = 0;
 }