diff --git a/contrib/03.callcc/callcc.c b/contrib/03.callcc/callcc.c
index eb519331..fef68f77 100644
--- a/contrib/03.callcc/callcc.c
+++ b/contrib/03.callcc/callcc.c
@@ -287,6 +287,8 @@ pic_callcc_callcc(pic_state *pic)
 void
 pic_init_callcc(pic_state *pic)
 {
-  pic_redefun(pic, pic->PICRIN_BASE, "call-with-current-continuation", pic_callcc_callcc);
-  pic_redefun(pic, pic->PICRIN_BASE, "call/cc", pic_callcc_callcc);
+  pic_deflibrary (pic, "(scheme base)") {
+    pic_redefun(pic, pic->PICRIN_BASE, "call-with-current-continuation", pic_callcc_callcc);
+    pic_redefun(pic, pic->PICRIN_BASE, "call/cc", pic_callcc_callcc);
+  }
 }
diff --git a/extlib/benz/include/picrin.h b/extlib/benz/include/picrin.h
index 0c950425..d7124e39 100644
--- a/extlib/benz/include/picrin.h
+++ b/extlib/benz/include/picrin.h
@@ -87,7 +87,7 @@ typedef struct {
 
   pic_code *ip;
 
-  struct pic_lib *lib;
+  struct pic_lib *lib, *prev_lib;
 
   pic_sym *sDEFINE, *sLAMBDA, *sIF, *sBEGIN, *sQUOTE, *sSETBANG;
   pic_sym *sQUASIQUOTE, *sUNQUOTE, *sUNQUOTE_SPLICING;
@@ -208,11 +208,12 @@ struct pic_lib *pic_open_library(pic_state *, pic_value);
 struct pic_lib *pic_find_library(pic_state *, pic_value);
 
 #define pic_deflibrary(pic, spec)                                       \
-  pic_deflibrary_helper_(pic, PIC_GENSYM(i), PIC_GENSYM(prev_lib), spec)
-#define pic_deflibrary_helper_(pic, i, prev_lib, spec)                  \
-  for (int i = 0; ! i; )                                                \
-    for (struct pic_lib *prev_lib; ! i; )                               \
-      for ((prev_lib = pic->lib), pic_open_library(pic, pic_read_cstr(pic, spec)), pic_in_library(pic, pic_read_cstr(pic, spec)); ! i++; pic->lib = prev_lib)
+  for (((assert(pic->prev_lib == NULL)),                                \
+        (pic->prev_lib = pic->lib),                                     \
+        (pic->lib = pic_open_library(pic, pic_read_cstr(pic, (spec))))); \
+       pic->prev_lib != NULL;                                           \
+       ((pic->lib = pic->prev_lib),                                     \
+        (pic->prev_lib = NULL)))
 
 void pic_import(pic_state *, pic_value);
 void pic_import_library(pic_state *, struct pic_lib *);
diff --git a/extlib/benz/state.c b/extlib/benz/state.c
index c17c841c..18b8e438 100644
--- a/extlib/benz/state.c
+++ b/extlib/benz/state.c
@@ -176,6 +176,7 @@ pic_open(int argc, char *argv[], char **envp)
   pic->PICRIN_BASE = pic_open_library(pic, pic_read_cstr(pic, "(picrin base)"));
   pic->PICRIN_USER = pic_open_library(pic, pic_read_cstr(pic, "(picrin user)"));
   pic->lib = pic->PICRIN_USER;
+  pic->prev_lib = NULL;
 
   /* standard I/O */
   pic->xSTDIN = pic_make_standard_port(pic, xstdin, PIC_PORT_IN);
diff --git a/src/main.c b/src/main.c
index 7d4f6fd1..03431ac4 100644
--- a/src/main.c
+++ b/src/main.c
@@ -42,10 +42,10 @@ pic_init_picrin(pic_state *pic)
 
   pic_deflibrary (pic, "(scheme base)") {
     pic_defun(pic, "features", pic_features);
-
-    pic_init_contrib(pic);
-    pic_load_piclib(pic);
   }
+
+  pic_init_contrib(pic);
+  pic_load_piclib(pic);
 }
 
 int