diff --git a/src/main/buffer.cl b/src/main/buffer.cl
index 5f84d86..8a21828 100644
--- a/src/main/buffer.cl
+++ b/src/main/buffer.cl
@@ -13,7 +13,7 @@
 ;;;; 
 ;;;; 
 
-(defvar *default-io-buffer-size* 4096
+(defvar *default-io-buffer-size* 16384
   "Default size of newly created I/O buffers.  This can be tuned to
 server needs.")
 
@@ -41,5 +41,6 @@ re-use."
 
 (defmacro with-io-buffer ((var) &body body)
   `(let ((,var (get-io-buffer)))
+     (declare (type simple-string ,var))
      (unwind-protect (progn ,@body)
        (release-io-buffer ,var))))