diff --git a/lib/activerecord-clean-db-structure/clean_dump.rb b/lib/activerecord-clean-db-structure/clean_dump.rb
index 8abb6c5..be05125 100644
--- a/lib/activerecord-clean-db-structure/clean_dump.rb
+++ b/lib/activerecord-clean-db-structure/clean_dump.rb
@@ -127,52 +127,34 @@ def run
 
       # Reduce 2+ lines of whitespace to one line of whitespace
       dump.gsub!(/\n{2,}/m, "\n\n")
+      # End the file with a single end-of-line character
+      dump.sub!(/\n*\z/m, "\n")
 
       if options[:order_column_definitions] == true
-        dump.replace(order_column_definitions(dump))
+        order_column_definitions
       end
     end
 
-    def order_column_definitions(source)
-      result = []
-
-      parse_column_name = ->(line) { line.match(/^    "?([^" ]+)/)[1] }
-      with_column_separator = ->(line) { line.sub(/,?\n$/, ",\n") }
-      without_column_separator = ->(line) { line.sub(/,\n$/, "\n") }
-
-      inside_table = false
-      columns = []
-
-      source.each_line do |source_line|
-        if source_line.start_with?("CREATE TABLE")
-          inside_table = true
-          columns = []
-          result << source_line
-        elsif source_line.start_with?(");")
-          if inside_table
-            inside_table = false
-            columns.sort_by!(&:first)
-
-            columns[0..-2].each do |_, line|
-              result << with_column_separator[line]
-            end
-
-            result << without_column_separator[columns.last[1]]
-          end
-
-          result << source_line
-        elsif inside_table
-          columns << [parse_column_name[source_line], source_line]
-        else
-          result << source_line
-        end
-      end
+    private
 
-      result.join
+    # Orders the columns definitions alphabetically
+    # - ignores quotes which surround column names that are equal to reserved PostgreSQL names.
+    # - keeps the columns at the top and places the constraints at the bottom.
+    def order_column_definitions
+      dump.gsub!(/^(?<table>CREATE TABLE .+?\(\n)(?<columns>.+?)(?=\n\);$)/m) do
+        table = $~[:table]
+        columns =
+          $~[:columns]
+          .split(",\n")
+          .sort_by { |column| column.delete('"') }
+          .partition { |column| !column.match?(/\A *CONSTRAINT/) }
+          .flatten
+          .join(",\n")
+
+        [table, columns].join
+      end
     end
 
-    private
-
     # Cleanup of schema_migrations values to prevent merge conflicts:
     # - sorts all values chronological
     # - places the comma's in front of each value (except for the first)