diff --git a/lib/strip_attributes.rb b/lib/strip_attributes.rb
index 13db4ed..cf72e64 100644
--- a/lib/strip_attributes.rb
+++ b/lib/strip_attributes.rb
@@ -52,12 +52,14 @@ def self.strip_record(record, options = {})
 
   def self.strip_string(value, options = {})
     return value unless value.is_a?(String)
+    # TODO: FUTURE CHANGE: return value if value.frozen?
 
     allow_empty      = options[:allow_empty]
     collapse_spaces  = options[:collapse_spaces]
     replace_newlines = options[:replace_newlines]
     regex            = options[:regex]
 
+    value = value.dup
     value.gsub!(regex, "") if regex
 
     if MULTIBYTE_SUPPORTED && Encoding.compatible?(value, MULTIBYTE_SPACE)
diff --git a/test/strip_attributes_test.rb b/test/strip_attributes_test.rb
index 317870e..f9d661f 100644
--- a/test/strip_attributes_test.rb
+++ b/test/strip_attributes_test.rb
@@ -13,6 +13,7 @@ def self.included(base)
     base.attribute :qux
     base.attribute :strip_me
     base.attribute :skip_me
+    base.attribute :frozen
   end
 end
 
@@ -203,6 +204,12 @@ def test_should_strip_and_allow_empty
     assert_equal "",            record.bang
   end
 
+  def test_should_strip_frozen_values
+    record = StripAllMockRecord.new(frozen: " ice ".freeze)
+    record.valid?
+    assert_equal "ice", record.frozen
+  end
+
   def test_should_collapse_duplicate_spaces
     record = CollapseDuplicateSpaces.new(@init_params)
     record.valid?