diff --git a/src/c/disassembler.d b/src/c/disassembler.d
index e996b6b8c..b3ad2838e 100644
--- a/src/c/disassembler.d
+++ b/src/c/disassembler.d
@@ -204,12 +204,19 @@ disassemble(cl_object bytecodes, cl_opcode *vector) {
     goto OPARG;
 
     /* OP_QUOTE
-       Sets VALUES(0) to an immediate value.
+       Sets REG0 to an immediate value.
     */
   case OP_QUOTE:          string = "QUOTE\t";
     GET_DATA(o, vector, data);
     goto ARG;
 
+    /* OP_CALLW
+       Sets REG0 to a result of calling an immediate value.
+    */
+  case OP_CALLW:          string = "CALLW\t";
+    GET_DATA(o, vector, data);
+    goto ARG;
+
     /* OP_CSET      n{arg}
        Replace constant with a computed value
     */
diff --git a/src/c/interpreter.d b/src/c/interpreter.d
index 3be5192bb..82caaad8f 100644
--- a/src/c/interpreter.d
+++ b/src/c/interpreter.d
@@ -410,7 +410,7 @@ ecl_interpret(cl_object frame, cl_object closure, cl_object bytecodes)
   lcl_env = ecl_cast_ptr(cl_object, &frame_lcl);
   ecl_cs_check(the_env, ihs);
   ecl_ihs_push(the_env, &ihs, bytecodes, closure, lcl_env);
-  ecl_stack_frame_open(the_env, lcl_env, nlcl);
+  if(nlcl) ecl_stack_frame_open(the_env, lcl_env, nlcl);
   frame_aux.t = t_frame;
   frame_aux.opened = 0;
   frame_aux.base = 0;
@@ -423,13 +423,21 @@ ecl_interpret(cl_object frame, cl_object closure, cl_object bytecodes)
       the_env->nvalues = 0;
       THREAD_NEXT;
     }
-    /* OP_QUOTE
+    /* OP_QUOTE     n{dat}
        Sets REG0 to an immediate value.
     */
     CASE(OP_QUOTE); {
       GET_DATA(reg0, vector, data);
       THREAD_NEXT;
     }
+    /* OP_CALLW     n{dat}
+       Calls the immediate value and sets REG0 to the result.
+    */
+    CASE(OP_CALLW); {
+      GET_DATA(reg0, vector, data);
+      ecl_apply_from_stack_frame(frame, reg0);
+      THREAD_NEXT;
+    }
     /* OP_VAR       n{lcl}
        OP_VARC      n{lex}
        OP_VARS      n{dat}
@@ -747,7 +755,7 @@ ecl_interpret(cl_object frame, cl_object closure, cl_object bytecodes)
     */
     CASE(OP_EXIT); {
       ecl_ihs_pop(the_env);
-      ecl_stack_frame_close(lcl_env);
+      if(nlcl) ecl_stack_frame_close(lcl_env);
       return reg0;
     }
     /* OP_FLET      nfun{arg}, fun1{object}
diff --git a/src/h/bytecodes.h b/src/h/bytecodes.h
index 9831e1085..ff57ad3be 100644
--- a/src/h/bytecodes.h
+++ b/src/h/bytecodes.h
@@ -13,6 +13,7 @@
 enum {
   OP_NOP,
   OP_QUOTE,
+  OP_CALLW,
   OP_ENDP,
   OP_CONS,
   OP_CAR,
@@ -176,6 +177,7 @@ typedef int16_t cl_opcode;
         static const int offsets[] = {\
   &&LBL_OP_NOP - &&LBL_OP_NOP,\
   &&LBL_OP_QUOTE - &&LBL_OP_NOP,\
+  &&LBL_OP_CALLW - &&LBL_OP_NOP,\
   &&LBL_OP_ENDP - &&LBL_OP_NOP,\
   &&LBL_OP_CONS - &&LBL_OP_NOP,\
   &&LBL_OP_CAR - &&LBL_OP_NOP,\