diff --git a/parse.y b/parse.y
index 63624cb408..1c808bd60e 100644
--- a/parse.y
+++ b/parse.y
@@ -694,6 +694,11 @@ static NODE* node_newnode_with_locals(struct parser_params *, enum node_type, VA
 static NODE* node_newnode(struct parser_params *, enum node_type, VALUE, VALUE, VALUE, const rb_code_location_t*);
 #define rb_node_newnode(type, a1, a2, a3, loc) node_newnode(p, (type), (a1), (a2), (a3), (loc))
 
+/* Make a new temporal node, which should not be appeared in the
+ * result AST and does not have node_id and location. */
+static NODE* node_new_temporal(struct parser_params *p, enum node_type type, VALUE a0, VALUE a1, VALUE a2);
+#define NODE_NEW_TEMPORAL(t,a0,a1,a2) node_new_temporal(p, (t),(VALUE)(a0),(VALUE)(a1),(VALUE)(a2))
+
 static NODE *nd_set_loc(NODE *nd, const YYLTYPE *loc);
 
 static int
@@ -1223,10 +1228,13 @@ rescued_expr(struct parser_params *p, NODE *arg, NODE *rescue,
 static void
 restore_defun(struct parser_params *p, NODE *name)
 {
-    YYSTYPE c = {.val = name->nd_cval};
+    NODE *save = name->nd_next;
+    YYSTYPE c = {.val = save->nd_cval};
     p->cur_arg = name->nd_vid;
     p->ctxt.in_def = c.ctxt.in_def;
     p->ctxt.shareable_constant_value = c.ctxt.shareable_constant_value;
+    p->max_numparam = (int)save->nd_nth;
+    numparam_pop(p, save->nd_head);
 }
 
 static void
@@ -2051,22 +2059,27 @@ expr		: command_call
 		| arg %prec tLBRACE_ARG
 		;
 
-def_name	: fname
-		    {
-			ID fname = get_id($1);
-			ID cur_arg = p->cur_arg;
-			YYSTYPE c = {.ctxt = p->ctxt};
-			numparam_name(p, fname);
-			local_push(p, 0);
-			p->cur_arg = 0;
-			p->ctxt.in_def = 1;
-			$<node>$ = NEW_NODE(NODE_SELF, /*vid*/cur_arg, /*mid*/fname, /*cval*/c.val, &@$);
-		    /*%%%*/
-		    /*%
+def_name        : fname
+                    {
+                        ID fname = get_id($1);
+                        ID cur_arg = p->cur_arg;
+                        YYSTYPE c = {.ctxt = p->ctxt};
+                        numparam_name(p, fname);
+                        NODE *save =
+                            NODE_NEW_TEMPORAL(NODE_SELF,
+                                              /*head*/numparam_push(p),
+                                              /*nth*/p->max_numparam,
+                                              /*cval*/c.val);
+                        local_push(p, 0);
+                        p->cur_arg = 0;
+                        p->ctxt.in_def = 1;
+                        $<node>$ = NEW_NODE(NODE_SELF, /*vid*/cur_arg, /*mid*/fname, /*args*/save, &@$);
+                    /*%%%*/
+                    /*%
 			$$ = NEW_RIPPER(fname, get_value($1), $$, &NULL_LOC);
 		    %*/
-		    }
-		;
+                    }
+                ;
 
 defn_head	: k_def def_name
 		    {
@@ -10551,11 +10564,18 @@ yylex(YYSTYPE *lval, YYLTYPE *yylloc, struct parser_params *p)
 #define LVAR_USED ((ID)1 << (sizeof(ID) * CHAR_BIT - 1))
 
 static NODE*
-node_newnode(struct parser_params *p, enum node_type type, VALUE a0, VALUE a1, VALUE a2, const rb_code_location_t *loc)
+node_new_temporal(struct parser_params *p, enum node_type type, VALUE a0, VALUE a1, VALUE a2)
 {
     NODE *n = rb_ast_newnode(p->ast, type);
 
     rb_node_init(n, type, a0, a1, a2);
+    return n;
+}
+
+static NODE*
+node_newnode(struct parser_params *p, enum node_type type, VALUE a0, VALUE a1, VALUE a2, const rb_code_location_t *loc)
+{
+    NODE *n = node_new_temporal(p, type, a0, a1, a2);
 
     nd_set_loc(n, loc);
     nd_set_node_id(n, parser_get_node_id(p));
diff --git a/test/ruby/test_syntax.rb b/test/ruby/test_syntax.rb
index 2ada566c84..7553cd74a6 100644
--- a/test/ruby/test_syntax.rb
+++ b/test/ruby/test_syntax.rb
@@ -1706,6 +1706,7 @@ eom
       ]
     }
 
+    assert_valid_syntax("proc {def foo(_);end;_1}")
     assert_valid_syntax("p { [_1 **2] }")
   end
 
diff --git a/version.h b/version.h
index d68d096838..1034f6f505 100644
--- a/version.h
+++ b/version.h
@@ -11,7 +11,7 @@
 # define RUBY_VERSION_MINOR RUBY_API_VERSION_MINOR
 #define RUBY_VERSION_TEENY 4
 #define RUBY_RELEASE_DATE RUBY_RELEASE_YEAR_STR"-"RUBY_RELEASE_MONTH_STR"-"RUBY_RELEASE_DAY_STR
-#define RUBY_PATCHLEVEL 204
+#define RUBY_PATCHLEVEL 205
 
 #include "ruby/version.h"
 #include "ruby/internal/abi.h"