5 files changed, 12 insertions, 0 deletions
diff --git a/node.c b/node.c
index 975ed9264f..f76e10e69b 100644
--- a/node.c
+++ b/node.c
@@ -93,6 +93,7 @@ rb_node_buffer_new(void)
 #define Qtrue ast->node_buffer->config->qtrue
 #define NIL_P ast->node_buffer->config->nil_p
 #define rb_hash_aset ast->node_buffer->config->hash_aset
+#define rb_hash_delete ast->node_buffer->config->hash_delete
 #define RB_OBJ_WRITE(old, slot, young) ast->node_buffer->config->obj_write((VALUE)(old), (VALUE *)(slot), (VALUE)(young))
 #endif
 
@@ -458,6 +459,13 @@ rb_ast_add_mark_object(rb_ast_t *ast, VALUE obj)
     rb_hash_aset(ast->node_buffer->mark_hash, obj, Qtrue);
 }
 
+void
+rb_ast_delete_mark_object(rb_ast_t *ast, VALUE obj)
+{
+    if (NIL_P(ast->node_buffer->mark_hash)) return;
+    rb_hash_delete(ast->node_buffer->mark_hash, obj);
+}
+
 VALUE
 rb_ast_tokens(rb_ast_t *ast)
 {
diff --git a/node.h b/node.h
index a25c4599eb..d8d104975a 100644
--- a/node.h
+++ b/node.h
@@ -67,6 +67,7 @@ void rb_ast_mark(rb_ast_t*);
 void rb_ast_update_references(rb_ast_t*);
 void rb_ast_free(rb_ast_t*);
 void rb_ast_add_mark_object(rb_ast_t*, VALUE);
+void rb_ast_delete_mark_object(rb_ast_t*, VALUE);
 void rb_ast_set_tokens(rb_ast_t*, VALUE);
 NODE *rb_ast_newnode(rb_ast_t*, enum node_type type, size_t size, size_t alignment);
 void rb_ast_delete_node(rb_ast_t*, NODE *n);
diff --git a/parse.y b/parse.y
index 1c2b11be86..86b24e49d3 100644
--- a/parse.y
+++ b/parse.y
@@ -8756,6 +8756,7 @@ heredoc_restore(struct parser_params *p, rb_strterm_heredoc_t *here)
     if (p->eofp) p->lex.nextline = Qnil;
     p->eofp = 0;
     xfree(term);
+    rb_ast_delete_mark_object(p->ast, line);
 }
 
 static int
diff --git a/ruby_parser.c b/ruby_parser.c
index 4ae92effb4..ba2c1e5d69 100644
--- a/ruby_parser.c
+++ b/ruby_parser.c
@@ -618,6 +618,7 @@ rb_parser_config_initialize(rb_parser_config_t *config)
     config->hash_new       = rb_hash_new;
     config->hash_aset      = rb_hash_aset;
     config->hash_lookup    = rb_hash_lookup;
+    config->hash_delete    = rb_hash_delete;
     config->ident_hash_new = rb_ident_hash_new;
 
     config->int2fix = int2fix;
diff --git a/rubyparser.h b/rubyparser.h
index da0be97db7..5805506831 100644
--- a/rubyparser.h
+++ b/rubyparser.h
@@ -1230,6 +1230,7 @@ typedef struct rb_parser_config_struct {
     VALUE (*hash_clear)(VALUE hash);
     VALUE (*hash_new)(void);
     VALUE (*hash_aset)(VALUE hash, VALUE key, VALUE val);
+    VALUE (*hash_delete)(VALUE hash, VALUE key);
     VALUE (*hash_lookup)(VALUE hash, VALUE key);
     VALUE (*ident_hash_new)(void);