diff --git a/extlib/benz/gc.c b/extlib/benz/gc.c
index 4acea528..1305ea79 100644
--- a/extlib/benz/gc.c
+++ b/extlib/benz/gc.c
@@ -645,7 +645,7 @@ gc_sweep_phase(pic_state *pic)
   struct heap_page *page;
   khiter_t it;
   khash_t(weak) *h;
-  khash_t(s) *s = &pic->oblist;
+  khash_t(oblist) *s = &pic->oblist;
   pic_sym *sym;
   struct pic_object *obj;
   size_t total = 0, inuse = 0;
@@ -670,7 +670,7 @@ gc_sweep_phase(pic_state *pic)
       continue;
     sym = kh_val(s, it);
     if (sym->gc_mark == PIC_GC_UNMARK) {
-      kh_del(s, s, it);
+      kh_del(oblist, s, it);
     }
   }
 
diff --git a/extlib/benz/include/picrin/state.h b/extlib/benz/include/picrin/state.h
index 59655643..2cef1abc 100644
--- a/extlib/benz/include/picrin/state.h
+++ b/extlib/benz/include/picrin/state.h
@@ -16,7 +16,7 @@ extern "C" {
 #include "picrin/read.h"
 #include "picrin/gc.h"
 
-KHASH_DECLARE(s, struct pic_string *, pic_sym *)
+KHASH_DECLARE(oblist, struct pic_string *, pic_sym *)
 
 typedef struct pic_checkpoint {
   PIC_OBJECT_HEADER
@@ -73,7 +73,7 @@ struct pic_state {
 
   pic_value features;
 
-  khash_t(s) oblist;            /* string to symbol */
+  khash_t(oblist) oblist;       /* string to symbol */
   int ucnt;
   struct pic_weak *globals;
   struct pic_weak *macros;
diff --git a/extlib/benz/state.c b/extlib/benz/state.c
index 961b832b..d2ac63c4 100644
--- a/extlib/benz/state.c
+++ b/extlib/benz/state.c
@@ -252,7 +252,7 @@ pic_open(pic_allocf allocf, void *userdata)
   pic->heap = pic_heap_open(pic);
 
   /* symbol table */
-  kh_init(s, &pic->oblist);
+  kh_init(oblist, &pic->oblist);
 
   /* unique symbol count */
   pic->ucnt = 0;
@@ -376,7 +376,7 @@ pic_open(pic_allocf allocf, void *userdata)
 void
 pic_close(pic_state *pic)
 {
-  khash_t(s) *h = &pic->oblist;
+  khash_t(oblist) *h = &pic->oblist;
   pic_allocf allocf = pic->allocf;
 
   /* clear out root objects */
@@ -420,7 +420,7 @@ pic_close(pic_state *pic)
   allocf(pic->userdata, pic->xpbase, 0);
 
   /* free global stacks */
-  kh_destroy(s, h);
+  kh_destroy(oblist, h);
 
   /* free GC arena */
   allocf(pic->userdata, pic->arena, 0);
diff --git a/extlib/benz/symbol.c b/extlib/benz/symbol.c
index 32d533d2..c7ee0969 100644
--- a/extlib/benz/symbol.c
+++ b/extlib/benz/symbol.c
@@ -7,17 +7,17 @@
 #define kh_pic_str_hash(a) (pic_str_hash(pic, (a)))
 #define kh_pic_str_cmp(a, b) (pic_str_cmp(pic, (a), (b)) == 0)
 
-KHASH_DEFINE(s, struct pic_string *, pic_sym *, kh_pic_str_hash, kh_pic_str_cmp)
+KHASH_DEFINE(oblist, struct pic_string *, pic_sym *, kh_pic_str_hash, kh_pic_str_cmp)
 
 pic_sym *
 pic_intern(pic_state *pic, struct pic_string *str)
 {
-  khash_t(s) *h = &pic->oblist;
+  khash_t(oblist) *h = &pic->oblist;
   pic_sym *sym;
   khiter_t it;
   int ret;
 
-  it = kh_put(s, h, str, &ret);
+  it = kh_put(oblist, h, str, &ret);
   if (ret == 0) {               /* if exists */
     sym = kh_val(h, it);
     pic_gc_protect(pic, pic_obj_value(sym));