diff --git a/lib/liquid/static_registers.rb b/lib/liquid/static_registers.rb
index b05056d..6f22f70 100644
--- a/lib/liquid/static_registers.rb
+++ b/lib/liquid/static_registers.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Liquid
   class StaticRegisters
     attr_reader :static_registers, :registers
diff --git a/test/unit/static_registers_unit_test.rb b/test/unit/static_registers_unit_test.rb
index 389cb3f..0db80cd 100644
--- a/test/unit/static_registers_unit_test.rb
+++ b/test/unit/static_registers_unit_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class StaticRegistersUnitTest < Minitest::Test