diff --git a/lib/lotus/utils/path_prefix.rb b/lib/lotus/utils/path_prefix.rb
index 1689299c..cf0b8620 100644
--- a/lib/lotus/utils/path_prefix.rb
+++ b/lib/lotus/utils/path_prefix.rb
@@ -1,9 +1,17 @@
+require 'lotus/utils/string'
+
 module Lotus
   module Utils
     # Prefixed string
     #
     # @since 0.1.0
-    class PathPrefix
+    class PathPrefix < Lotus::Utils::String
+      # Path separator
+      #
+      # @since x.x.x
+      # @api private
+      DEFAULT_SEPARATOR = '/'.freeze
+
       # Initialize the path prefix
       #
       # @param string [::String] the prefix value
@@ -12,9 +20,11 @@ class PathPrefix
       # @return [PathPrefix] self
       #
       # @since 0.1.0
-      def initialize(string = nil, separator = '/')
+      #
+      # @see Lotus::Utils::PathPrefix::DEFAULT_SEPARATOR
+      def initialize(string = nil, separator = DEFAULT_SEPARATOR)
+        super(string)
         @separator = separator
-        @string    = string.to_s
       end
 
       # Joins self with the given token.
@@ -68,53 +78,37 @@ def join(*strings)
       #   path_prefix.relative_join 'new', '_' # => 'posts_new'
       def relative_join(strings, separator = @separator)
         raise TypeError if separator.nil?
-        relativize [@string, strings].join(separator), separator
-      end
 
-      # Returns the hash of the internal string
-      #
-      # @return [Fixnum]
-      #
-      # @since 0.3.0
-      def hash
-        @string.hash
-      end
-
-      # Returns a string representation
-      #
-      # @return [String]
-      #
-      # @since 0.3.0
-      def to_s
-        @string
+        self.class.new(
+          relativize(
+            [@string.gsub(@separator, separator), strings].join(separator),
+            separator
+          ),
+          @separator
+        )
       end
 
-      alias_method :to_str,  :to_s
-
-      # Equality
-      #
-      # @return [TrueClass,FalseClass]
-      #
-      # @since 0.3.0
-      def ==(other)
-        to_s == other
-      end
-
-      alias_method :eql?, :==
-
       private
+      # @since 0.1.0
+      # @api private
       attr_reader :separator
 
+      # @since 0.1.0
+      # @api private
       def absolutize(string)
         string.tap do |s|
           s.prepend(separator) unless absolute?(s)
         end
       end
 
+      # @since 0.1.0
+      # @api private
       def absolute?(string)
         string.start_with?(separator)
       end
 
+      # @since 0.1.0
+      # @api private
       def relativize(string, separator = @separator)
         string.
           gsub(%r{(?<!:)#{ separator * 2 }}, separator).
diff --git a/test/path_prefix_test.rb b/test/path_prefix_test.rb
index 4d7db0fd..42f2c960 100644
--- a/test/path_prefix_test.rb
+++ b/test/path_prefix_test.rb
@@ -13,6 +13,12 @@
   end
 
   describe '#join' do
+    it 'returns a PathPrefix' do
+      prefix = Lotus::Utils::PathPrefix.new('orders', '?').join('new')
+      prefix.must_be_kind_of(Lotus::Utils::PathPrefix)
+      prefix.__send__(:separator).must_equal('?')
+    end
+
     it 'joins a string' do
       prefix = Lotus::Utils::PathPrefix.new('fruits')
       prefix.join('peaches').must_equal '/fruits/peaches'
@@ -46,6 +52,12 @@
   end
 
   describe '#relative_join' do
+    it 'returns a PathPrefix' do
+      prefix = Lotus::Utils::PathPrefix.new('orders', '&').relative_join('new')
+      prefix.must_be_kind_of(Lotus::Utils::PathPrefix)
+      prefix.__send__(:separator).must_equal('&')
+    end
+
     it 'joins a string without prefixing with separator' do
       prefix = Lotus::Utils::PathPrefix.new('fruits')
       prefix.relative_join('peaches').must_equal 'fruits/peaches'
@@ -76,6 +88,11 @@
       prefix.relative_join('_cherries', '_').must_equal 'fruits_cherries'
     end
 
+    it 'changes all the occurences of the current separator with the given one' do
+      prefix = Lotus::Utils::PathPrefix.new('?fruits', '?')
+      prefix.relative_join('cherries', '_').must_equal 'fruits_cherries'
+    end
+
     it 'raises error if the given separator is nil' do
       prefix = Lotus::Utils::PathPrefix.new('fruits')
       -> { prefix.relative_join('_cherries', nil) }.must_raise TypeError