diff --git a/lib/typeprof/core/ast/meta.rb b/lib/typeprof/core/ast/meta.rb
index 8452d986..914476db 100644
--- a/lib/typeprof/core/ast/meta.rb
+++ b/lib/typeprof/core/ast/meta.rb
@@ -240,6 +240,22 @@ def initialize(raw_node, members, kind, lenv)
       def subnodes = { block_body: }
       def attrs = { static_cpath:, members:, kind: }
 
+      # A method written in the block body (e.g. a custom initialize)
+      # overrides the auto-generated one, which should then be hidden
+      # from the RBS output.
+      def block_defines_method?(singleton, mid)
+        return false unless @block_body
+        found = false
+        @block_body.traverse do |event, node|
+          if event == :enter && node.is_a?(DefNode) &&
+             node.singleton == singleton && node.mid == mid &&
+             node.lenv.cref.cpath == @static_cpath
+            found = true
+          end
+        end
+        found
+      end
+
       # Interface expected by MethodDefBox
       def req_positionals = @kind == :struct ? @members : []
       def opt_positionals = []
diff --git a/lib/typeprof/core/service.rb b/lib/typeprof/core/service.rb
index ce5ffd60..52d112e3 100644
--- a/lib/typeprof/core/service.rb
+++ b/lib/typeprof/core/service.rb
@@ -499,6 +499,7 @@ def dump_declarations(path)
               end
               # Output method definitions from meta nodes (StructNewNode etc.)
               node.boxes(:mdef) do |mdef|
+                next if node.is_a?(AST::StructNewNode) && node.block_defines_method?(mdef.singleton, mdef.mid)
                 out << "  " * stack.size + "def #{ mdef.singleton ? "self." : "" }#{ mdef.mid }: " + mdef.show(@options[:output_parameter_names])
               end
             else
diff --git a/scenario/misc/struct_new.rb b/scenario/misc/struct_new.rb
index 9357266b..bef9f469 100644
--- a/scenario/misc/struct_new.rb
+++ b/scenario/misc/struct_new.rb
@@ -69,3 +69,25 @@ def self.[]: (Integer) -> Baz
   def set_label: -> String
   def ivar: -> String
 end
+
+## update
+# https://github.com/ruby/typeprof/issues/458
+# A user-defined initialize in the block overrides the auto-generated one,
+# so the RBS output must contain only the user-defined signature.
+Pt = Struct.new(:x, :y) do
+  def initialize(x = 0, y = 0)
+    super
+  end
+end
+Pt.new
+Pt.new(3, 4)
+
+## assert
+class Pt
+  def x: -> Integer
+  def x=: (untyped) -> untyped
+  def y: -> Integer
+  def y=: (untyped) -> untyped
+  def self.[]: (Integer, Integer) -> Pt
+  def initialize: (?Integer, ?Integer) -> void
+end