diff --git a/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb b/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
index d5a603cadc..98126249df 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
@@ -84,7 +84,7 @@ module ActiveRecord
             $1
           # Character types
           when /\A\(?'(.*)'::.*\b(?:character varying|bpchar|text)\z/m
-            $1
+            $1.gsub(/''/, "'")
           # Binary data types
           when /\A'(.*)'::bytea\z/m
             $1
diff --git a/activerecord/test/cases/defaults_test.rb b/activerecord/test/cases/defaults_test.rb
index e0cf4adf13..7e3d91e08c 100644
--- a/activerecord/test/cases/defaults_test.rb
+++ b/activerecord/test/cases/defaults_test.rb
@@ -39,6 +39,31 @@ class DefaultTest < ActiveRecord::TestCase
   end
 end
 
+class DefaultStringsTest < ActiveRecord::TestCase
+  class DefaultString < ActiveRecord::Base; end
+
+  setup do
+    @connection = ActiveRecord::Base.connection
+    @connection.create_table :default_strings do |t|
+      t.string :string_col, default: "Smith"
+      t.string :string_col_with_quotes, default: "O'Connor"
+    end
+    DefaultString.reset_column_information
+  end
+
+  def test_default_strings
+    assert_equal "Smith", DefaultString.new.string_col
+  end
+
+  def test_default_strings_containing_single_quotes
+    assert_equal "O'Connor", DefaultString.new.string_col_with_quotes
+  end
+
+  teardown do
+    @connection.drop_table :default_strings
+  end
+end
+
 if current_adapter?(:MysqlAdapter, :Mysql2Adapter)
   class DefaultsTestWithoutTransactionalFixtures < ActiveRecord::TestCase
     # ActiveRecord::Base#create! (and #save and other related methods) will