diff --git a/imemo.c b/imemo.c
index 346fae3b869ca0..2dd05b29f9df3b 100644
--- a/imemo.c
+++ b/imemo.c
@@ -167,11 +167,14 @@ rb_imemo_fields_clone(VALUE fields_obj)
     VALUE clone;
 
     if (rb_shape_too_complex_p(shape_id)) {
-        clone = rb_imemo_fields_new_complex(rb_imemo_fields_owner(fields_obj), 0);
-        RBASIC_SET_SHAPE_ID(clone, shape_id);
         st_table *src_table = rb_imemo_fields_complex_tbl(fields_obj);
-        st_table *dest_table = rb_imemo_fields_complex_tbl(clone);
+
+        st_table *dest_table = xcalloc(1, sizeof(st_table));
+        clone = rb_imemo_fields_new_complex_tbl(rb_imemo_fields_owner(fields_obj), dest_table);
+
         st_replace(dest_table, src_table);
+        RBASIC_SET_SHAPE_ID(clone, shape_id);
+
         st_foreach(dest_table, imemo_fields_complex_wb_i, (st_data_t)clone);
     }
     else {
diff --git a/parse.y b/parse.y
index 6fac3b8ec79760..00c5aef6d267c3 100644
--- a/parse.y
+++ b/parse.y
@@ -3026,13 +3026,13 @@ rb_parser_ary_free(rb_parser_t *p, rb_parser_ary_t *ary)
                     }
                 ;
 
-%rule mlhs(item) <node>
+%rule mlhs_items(item) <node>
                 : item
                     {
                         $$ = NEW_LIST($1, &@$);
                     /*% ripper: mlhs_add!(mlhs_new!, $:1) %*/
                     }
-                | mlhs(item) ',' item
+                | mlhs_items(item) ',' item
                     {
                         $$ = list_append(p, $1, $3);
                     /*% ripper: mlhs_add!($:1, $:3) %*/
@@ -3676,7 +3676,7 @@ mlhs_basic	: mlhs_head
                         $$ = NEW_MASGN($1, $3, &@$);
                     /*% ripper: mlhs_add_star!($:1, $:3) %*/
                     }
-                | mlhs_head tSTAR mlhs_node ',' mlhs(mlhs_item)
+                | mlhs_head tSTAR mlhs_node ',' mlhs_items(mlhs_item)
                     {
                         $$ = NEW_MASGN($1, NEW_POSTARG($3,$5,&@$), &@$);
                     /*% ripper: mlhs_add_post!(mlhs_add_star!($:1, $:3), $:5) %*/
@@ -3686,7 +3686,7 @@ mlhs_basic	: mlhs_head
                         $$ = NEW_MASGN($1, NODE_SPECIAL_NO_NAME_REST, &@$);
                     /*% ripper: mlhs_add_star!($:1, Qnil) %*/
                     }
-                | mlhs_head tSTAR ',' mlhs(mlhs_item)
+                | mlhs_head tSTAR ',' mlhs_items(mlhs_item)
                     {
                         $$ = NEW_MASGN($1, NEW_POSTARG(NODE_SPECIAL_NO_NAME_REST, $4, &@$), &@$);
                     /*% ripper: mlhs_add_post!(mlhs_add_star!($:1, Qnil), $:4) %*/
@@ -3696,7 +3696,7 @@ mlhs_basic	: mlhs_head
                         $$ = NEW_MASGN(0, $2, &@$);
                     /*% ripper: mlhs_add_star!(mlhs_new!, $:2) %*/
                     }
-                | tSTAR mlhs_node ',' mlhs(mlhs_item)
+                | tSTAR mlhs_node ',' mlhs_items(mlhs_item)
                     {
                         $$ = NEW_MASGN(0, NEW_POSTARG($2,$4,&@$), &@$);
                     /*% ripper: mlhs_add_post!(mlhs_add_star!(mlhs_new!, $:2), $:4) %*/
@@ -3706,7 +3706,7 @@ mlhs_basic	: mlhs_head
                         $$ = NEW_MASGN(0, NODE_SPECIAL_NO_NAME_REST, &@$);
                     /*% ripper: mlhs_add_star!(mlhs_new!, Qnil) %*/
                     }
-                | tSTAR ',' mlhs(mlhs_item)
+                | tSTAR ',' mlhs_items(mlhs_item)
                     {
                         $$ = NEW_MASGN(0, NEW_POSTARG(NODE_SPECIAL_NO_NAME_REST, $3, &@$), &@$);
                     /*% ripper: mlhs_add_post!(mlhs_add_star!(mlhs_new!, Qnil), $:3) %*/
@@ -4917,17 +4917,17 @@ f_marg		: f_norm_arg
                 ;
 
 
-f_margs		: mlhs(f_marg)
+f_margs		: mlhs_items(f_marg)
                     {
                         $$ = NEW_MASGN($1, 0, &@$);
                     /*% ripper: $:1 %*/
                     }
-                | mlhs(f_marg) ',' f_rest_marg
+                | mlhs_items(f_marg) ',' f_rest_marg
                     {
                         $$ = NEW_MASGN($1, $3, &@$);
                     /*% ripper: mlhs_add_star!($:1, $:3) %*/
                     }
-                | mlhs(f_marg) ',' f_rest_marg ',' mlhs(f_marg)
+                | mlhs_items(f_marg) ',' f_rest_marg ',' mlhs_items(f_marg)
                     {
                         $$ = NEW_MASGN($1, NEW_POSTARG($3, $5, &@$), &@$);
                     /*% ripper: mlhs_add_post!(mlhs_add_star!($:1, $:3), $:5) %*/
@@ -4937,7 +4937,7 @@ f_margs		: mlhs(f_marg)
                         $$ = NEW_MASGN(0, $1, &@$);
                     /*% ripper: mlhs_add_star!(mlhs_new!, $:1) %*/
                     }
-                | f_rest_marg ',' mlhs(f_marg)
+                | f_rest_marg ',' mlhs_items(f_marg)
                     {
                         $$ = NEW_MASGN(0, NEW_POSTARG($1, $3, &@$), &@$);
                     /*% ripper: mlhs_add_post!(mlhs_add_star!(mlhs_new!, $:1), $:3) %*/