diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5563753..4496cea 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,10 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## 1.1.1
+
+- Freeze values returned from helper methods.
+
 ## 1.1.0
 
 ### Added
diff --git a/VERSION b/VERSION
index 9084fa2..524cb55 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-1.1.0
+1.1.1
diff --git a/lib/support_table_data.rb b/lib/support_table_data.rb
index 63445c0..1b68e0f 100644
--- a/lib/support_table_data.rb
+++ b/lib/support_table_data.rb
@@ -225,7 +225,7 @@ def define_support_table_instance_attribute_helper(method_name, attribute_value)
 
       class_eval <<~RUBY, __FILE__, __LINE__ + 1
         def self.#{method_name}
-          #{attribute_value.inspect}
+          #{attribute_value.inspect}.freeze
         end
       RUBY
     end
diff --git a/spec/support_table_data_spec.rb b/spec/support_table_data_spec.rb
index ebec39f..30ca36b 100644
--- a/spec/support_table_data_spec.rb
+++ b/spec/support_table_data_spec.rb
@@ -153,6 +153,11 @@
       expect(Group.support_table_attribute_helpers).to match_array ["group_id", "name"]
       expect(Color.support_table_attribute_helpers).to match_array []
     end
+
+    it "returns frozen values" do
+      expect(Group.primary_group_id).to be_frozen
+      expect(Group.primary_name).to be_frozen
+    end
   end
 
   describe "protected_instance?" do