diff --git a/contrib/10.readline/src/readline.c b/contrib/10.readline/src/readline.c
index f9de7060..fb043dd7 100644
--- a/contrib/10.readline/src/readline.c
+++ b/contrib/10.readline/src/readline.c
@@ -6,6 +6,7 @@
 forget to use the C++ extern "C" to get it to compile.
 */
 #include <editline/readline.h>
+#include <editline/history.h>
 #include "picrin.h"
 #include "picrin/pair.h"
 #include "picrin/string.h"
@@ -130,7 +131,7 @@ pic_rl_read_history(pic_state *pic)
   pic_get_args(pic, "z", &filename);
 
   if(read_history(filename))
-    pic_errorf(pic, "cannot read history file :%s", filename);
+    pic_errorf(pic, "cannot read history file : %s", filename);
   
   return pic_undef_value();
 }
@@ -143,7 +144,7 @@ pic_rl_write_history(pic_state *pic)
   pic_get_args(pic, "z", &filename);
 
   if(write_history(filename))
-    pic_errorf(pic, "cannot write history file:%s", filename);
+    pic_errorf(pic, "cannot write history file: %s", filename);
   
   return pic_undef_value();
 }
diff --git a/contrib/10.readline/t/test.scm b/contrib/10.readline/t/test.scm
index af695621..fa5c8a08 100644
--- a/contrib/10.readline/t/test.scm
+++ b/contrib/10.readline/t/test.scm
@@ -20,31 +20,30 @@
 ;; (readline "prompt")
   
 (define testfile "./picrin_readline_test_file")
-
 (test-begin)
 
 (test 0 (history-length))
-(add-history "0")
+(add-history "1")
 (test 1 (history-length))
-(let loop ((n 1))
-  (if (> 10 n)
+(let loop ((n 2))
+  (if (>= 10 n)
       (begin
         (add-history (number->string n))
         (loop (+ n 1)))))
 (test 10 (history-length))
 (stifle-history 7)
-(test 7 (history-length))
-(add-history "10")
+(test 10 (history-length))
+(add-history "11")
 (test 7 (history-length))
 (test #t (history-stifled?))
 (unstifle-history)
 (test #f (history-stifled?))
 (test 7 (history-length))
-(add-history "11")
+(add-history "12")
 (test 8 (history-length))
-(test "10" (history-get 11))
+(test "11" (history-get 11))
 (remove-history 1)
-(test "10" (history-get 11))
+(test "11" (history-get 11))
 (test 7 (history-length))
 (write-history testfile)
 (test 7 (history-length))