diff --git a/lib/ipaddress/ipv4.rb b/lib/ipaddress/ipv4.rb
index a798a24..34685a2 100644
--- a/lib/ipaddress/ipv4.rb
+++ b/lib/ipaddress/ipv4.rb
@@ -461,7 +461,15 @@ def <=>(oth)
       return prefix <=> oth.prefix if to_u32 == oth.to_u32  
       to_u32 <=> oth.to_u32
     end
-    
+
+    def eql?(oth)
+      self == oth
+    end
+
+    def hash
+      [ to_u32, prefix.to_u32 ].hash
+    end
+
     #
     # Returns the number of IP addresses included
     # in the network. It also counts the network
@@ -680,11 +688,13 @@ def supernet(new_prefix)
     # a power of two.
     #
     def subnet(subprefix)
-      unless ((@prefix.to_i)..32).include? subprefix
+      # convert to integer in case subprefix is an IPAddress::Prefix
+      subprefix_i = subprefix.to_i
+      unless ((@prefix.to_i)..32).include? subprefix_i
         raise ArgumentError, "New prefix must be between #@prefix and 32"
       end
-      Array.new(2**(subprefix-@prefix.to_i)) do |i|
-        self.class.parse_u32(network_u32+(i*(2**(32-subprefix))), subprefix)
+      Array.new(2**(subprefix_i-@prefix.to_i)) do |i|
+        self.class.parse_u32(network_u32+(i*(2**(32-subprefix_i))), subprefix_i)
       end
     end
 
diff --git a/lib/ipaddress/ipv6.rb b/lib/ipaddress/ipv6.rb
index 33d4d19..3c601df 100644
--- a/lib/ipaddress/ipv6.rb
+++ b/lib/ipaddress/ipv6.rb
@@ -482,6 +482,14 @@ def <=>(oth)
       to_u128 <=> oth.to_u128
     end
 
+    def eql?(oth)
+      self == oth
+    end
+
+    def hash
+      [ to_u128, prefix.to_u128 ].hash
+    end
+
     #
     # Returns the address portion of an IP in binary format,
     # as a string containing a sequence of 0 and 1
diff --git a/lib/ipaddress/prefix.rb b/lib/ipaddress/prefix.rb
index f3d585d..77ff8b9 100644
--- a/lib/ipaddress/prefix.rb
+++ b/lib/ipaddress/prefix.rb
@@ -53,6 +53,14 @@ def <=>(oth)
       @prefix <=> oth.to_i
     end
 
+    def eql?(oth)
+      self == oth
+    end
+
+    def hash
+      to_i.hash
+    end
+
     #
     # Sums two prefixes or a prefix to a 
     # number, returns a Fixnum
@@ -260,6 +268,6 @@ def host_prefix
       128 - @prefix
     end
 
-  end # class Prefix123 < Prefix
+  end # class Prefix128 < Prefix
 
 end # module IPAddress
diff --git a/test/ipaddress/ipv4_test.rb b/test/ipaddress/ipv4_test.rb
index 6d6386f..d0032ab 100644
--- a/test/ipaddress/ipv4_test.rb
+++ b/test/ipaddress/ipv4_test.rb
@@ -526,7 +526,22 @@ def test_classmethod_parse_classful
     end
     assert_raise(ArgumentError){ @klass.parse_classful("192.168.256.257") }
   end
-  
+
+  def test_hash_equality
+    ip1 = @klass.new("10.0.1.1/24")
+    ip2 = @klass.new("10.0.1.1/24")
+    assert_equal ip1.hash, ip2.hash
+    assert_equal ip1.eql?( ip2 ), true
+  end
+
+  def test_subnet_prefix_acceptance
+    ip = @klass.new("10.0.1.1/24")
+    ip2 = @klass.new("10.0.1.1/29")
+    subnet1 = ip.subnet(29)
+    subnet2 = ip.subnet(ip2.prefix)
+    assert_equal subnet1, subnet2
+  end
+
 end # class IPv4Test
 
   
diff --git a/test/ipaddress/ipv6_test.rb b/test/ipaddress/ipv6_test.rb
index 9d9ff3e..34cf6f2 100644
--- a/test/ipaddress/ipv6_test.rb
+++ b/test/ipaddress/ipv6_test.rb
@@ -418,5 +418,12 @@ def test_method_ipv6?
   def test_mapped?
     assert_equal true, @ip.mapped?
   end
+
+  def test_hash_equality
+    ip1 = @klass.new("2001:db8::8:800:200c:417a/64")
+    ip2 = @klass.new("2001:db8::8:800:200c:417a/64")
+    assert_equal ip1.hash, ip2.hash
+    assert_equal ip1.eql?( ip2 ), true
+  end
   
 end # class IPv6MappedTest
diff --git a/test/ipaddress/prefix_test.rb b/test/ipaddress/prefix_test.rb
index bff812e..6e523b5 100644
--- a/test/ipaddress/prefix_test.rb
+++ b/test/ipaddress/prefix_test.rb
@@ -156,4 +156,11 @@ def test_method_to_u32
     end
   end
 
+  def test_hash_equality
+    prefix1 = @klass.new(23)
+    prefix2 = @klass.new(23)
+    assert_equal prefix1.hash, prefix2.hash
+    assert_equal prefix1.eql?( prefix2 ), true
+  end
+
 end # class Prefix128Test