--- IO-AIO/AIO.xs	2016/02/23 19:42:43	1.239
+++ IO-AIO/AIO.xs	2016/02/23 19:42:59	1.240
@@ -1318,7 +1318,7 @@
 #endif
 
             if (svlen < need)
-              svptr = SvGROW (arg, need + 1);
+              svptr = SvGROW (arg, need);
           }
         else
           svptr = (char *)SvIV (arg);