1 files changed, 5 insertions, 0 deletions
diff --git a/rjit_c.rb b/rjit_c.rb
index 72e8221cbc..949040e10e 100644
--- a/rjit_c.rb
+++ b/rjit_c.rb
@@ -1483,6 +1483,7 @@ module RubyVM::RJIT # :nodoc: all
       type: [CType::Immediate.parse("uint8_t"), Primitive.cexpr!("OFFSETOF((*((struct rb_shape *)NULL)), type)")],
       size_pool_index: [CType::Immediate.parse("uint8_t"), Primitive.cexpr!("OFFSETOF((*((struct rb_shape *)NULL)), size_pool_index)")],
       parent_id: [self.shape_id_t, Primitive.cexpr!("OFFSETOF((*((struct rb_shape *)NULL)), parent_id)")],
+      ancestor_index: [CType::Pointer.new { self.redblack_node_t }, Primitive.cexpr!("OFFSETOF((*((struct rb_shape *)NULL)), ancestor_index)")],
     )
   end
 
@@ -1641,6 +1642,10 @@ module RubyVM::RJIT # :nodoc: all
     CType::Bool.new
   end
 
+  def C.redblack_node_t
+    CType::Stub.new(:redblack_node_t)
+  end
+
   def C.ccan_list_node
     CType::Stub.new(:ccan_list_node)
   end