diff --git a/include/picrin/irep.h b/include/picrin/irep.h
index 8e032d5d..7cdbc41d 100644
--- a/include/picrin/irep.h
+++ b/include/picrin/irep.h
@@ -11,6 +11,7 @@ enum pic_opcode {
   OP_GREF,
   OP_GSET,
   OP_LREF,
+  OP_CREF,
   OP_JMP,
   OP_JMPIF,
   OP_CALL,
@@ -32,6 +33,10 @@ struct pic_code {
   union {
     double f;
     int i;
+    struct {
+      short depth;
+      short idx;
+    } c;
   } u;
 };
 
diff --git a/src/codegen.c b/src/codegen.c
index e7a7bdf1..df335f10 100644
--- a/src/codegen.c
+++ b/src/codegen.c
@@ -506,6 +506,9 @@ print_irep(pic_state *pic, struct pic_irep *irep)
     case OP_LREF:
       printf("OP_LREF\t%d\n", irep->code[i].u.i);
       break;
+    case OP_CREF:
+      printf("OP_CREF\t%d\t%d\n", irep->code[i].u.c.depth, irep->code[i].u.c.idx);
+      break;
     case OP_JMP:
       printf("OP_JMP\t%d\n", irep->code[i].u.i);
       break;
diff --git a/src/vm.c b/src/vm.c
index 946eaf04..0847794f 100644
--- a/src/vm.c
+++ b/src/vm.c
@@ -118,9 +118,10 @@ pic_run(pic_state *pic, struct pic_proc *proc, pic_value args)
 #if PIC_DIRECT_THREADED_VM
   static void *oplabels[] = {
     &&L_OP_POP, &&L_OP_PUSHNIL, &&L_OP_PUSHTRUE, &&L_OP_PUSHFALSE, &&L_OP_PUSHNUM,
-    &&L_OP_PUSHCONST, &&L_OP_GREF, &&L_OP_GSET, &&L_OP_LREF, &&L_OP_JMP, &&L_OP_JMPIF,
-    &&L_OP_CALL, &&L_OP_RET, &&L_OP_LAMBDA, &&L_OP_CONS, &&L_OP_CAR, &&L_OP_CDR,
-    &&L_OP_NILP, &&L_OP_ADD, &&L_OP_SUB, &&L_OP_MUL, &&L_OP_DIV, &&L_OP_STOP
+    &&L_OP_PUSHCONST, &&L_OP_GREF, &&L_OP_GSET, &&L_OP_LREF, &&L_OP_CREF,
+    &&L_OP_JMP, &&L_OP_JMPIF, &&L_OP_CALL, &&L_OP_RET, &&L_OP_LAMBDA, &&L_OP_CONS,
+    &&L_OP_CAR, &&L_OP_CDR, &&L_OP_NILP, &&L_OP_ADD, &&L_OP_SUB, &&L_OP_MUL,
+    &&L_OP_DIV, &&L_OP_STOP
   };
 #endif
 
@@ -177,6 +178,17 @@ pic_run(pic_state *pic, struct pic_proc *proc, pic_value args)
       PUSH(pic->ci->fp[pc->u.i]);
       NEXT;
     }
+    CASE(OP_CREF) {
+      int depth = pc->u.c.depth;
+      struct pic_env *env;
+
+      env = pic_proc_ptr(*pic->ci->fp)->env;
+      while (depth--) {
+	env = env->up;
+      }
+      PUSH(env->values[pc->u.c.idx]);
+      NEXT;
+    }
     CASE(OP_JMP) {
       pc += pc->u.i;
       JUMP;