diff --git a/piclib/scheme/base.scm b/piclib/scheme/base.scm
index 186b2f57..efb0a61a 100644
--- a/piclib/scheme/base.scm
+++ b/piclib/scheme/base.scm
@@ -7,6 +7,20 @@
   (export define set! lambda quote
           if begin define-syntax)
 
+  ;; call/cc
+
+  (define real-callcc call-with-current-continuation)
+
+  (set! call-with-current-continuation
+        (lambda (f)
+          (real-callcc
+           (lambda (c)
+             (f (lambda args (apply continue c args)))))))
+
+  (define call/cc call-with-current-continuation)
+
+  (export call/cc)
+
   ;; core syntax
 
   (define-syntax syntax-error
@@ -840,6 +854,10 @@
 
   (export define-record-type)
 
+  (export (rename floor-remainder modulo)
+          (rename truncate-quotient quotient)
+          (rename truncate-remainder remainder))
+
   ;; 6.4 Pairs and lists
 
   (export pair?
@@ -920,7 +938,10 @@
   (define (string . objs)
     (list->string objs))
 
-  (export string string->list list->string)
+  (export string
+          string->list
+          list->string
+          (rename string-copy substring))
 
   ;; 6.8. Vector
 
diff --git a/src/init.c b/src/init.c
index 76b51d35..6ff9eac0 100644
--- a/src/init.c
+++ b/src/init.c
@@ -35,11 +35,19 @@ pic_libraries(pic_state *pic)
   return libs;
 }
 
+void pic_init_eval(pic_state *);
+void pic_init_file(pic_state *);
+void pic_init_load(pic_state *);
+void pic_init_macro2(pic_state *);
+void pic_init_system(pic_state *);
+void pic_init_time(pic_state *);
+
 void pic_init_contrib(pic_state *);
+
 void pic_load_piclib(pic_state *);
 
 void
-pic_init_misc(pic_state *pic)
+pic_init_picrin(pic_state *pic)
 {
   pic_deflibrary (pic, "(picrin library)") {
     pic_defun(pic, "libraries", pic_libraries);
@@ -47,7 +55,16 @@ pic_init_misc(pic_state *pic)
 
   pic_deflibrary (pic, "(scheme base)") {
     pic_defun(pic, "features", pic_features);
+
+    pic_init_eval(pic);
+    pic_init_file(pic);
+    pic_init_load(pic);
+    pic_init_macro2(pic);
+    pic_init_system(pic);
+    pic_init_time(pic);
+
     pic_init_contrib(pic);
+
     pic_load_piclib(pic);
   }
 }
diff --git a/src/main.c b/src/main.c
index 617d4a0d..d37bbdca 100644
--- a/src/main.c
+++ b/src/main.c
@@ -13,6 +13,8 @@ main(int argc, char *argv[], char **envp)
 
   pic = pic_open(argc, argv, envp);
 
+  pic_init_picrin(pic);
+
   pic_try {
     pic_import(pic, pic_read_cstr(pic, "(picrin main)"));
     pic_funcall(pic, "main", pic_nil_value());