diff --git a/lib/ipaddr.rb b/lib/ipaddr.rb
index 725ff30..6b67d7e 100644
--- a/lib/ipaddr.rb
+++ b/lib/ipaddr.rb
@@ -368,7 +368,7 @@ def _ipv4_compat?             # :nodoc:
   # into an IPv4-mapped IPv6 address.
   def ipv4_mapped
     if !ipv4?
-      raise InvalidAddressError, "not an IPv4 address: #{@addr}"
+      raise InvalidAddressError, "not an IPv4 address: #{to_s}"
     end
     clone = self.clone.set(@addr | 0xffff00000000, Socket::AF_INET6)
     clone.instance_variable_set(:@mask_addr, @mask_addr | 0xffffffffffffffffffffffff00000000)
@@ -380,7 +380,7 @@ def ipv4_mapped
   def ipv4_compat
     warn "IPAddr\##{__callee__} is obsolete", uplevel: 1 if $VERBOSE
     if !ipv4?
-      raise InvalidAddressError, "not an IPv4 address: #{@addr}"
+      raise InvalidAddressError, "not an IPv4 address: #{to_s}"
     end
     clone = self.clone.set(@addr, Socket::AF_INET6)
     clone.instance_variable_set(:@mask_addr, @mask_addr | 0xffffffffffffffffffffffff00000000)
@@ -413,7 +413,7 @@ def reverse
   # Returns a string for DNS reverse lookup compatible with RFC3172.
   def ip6_arpa
     if !ipv6?
-      raise InvalidAddressError, "not an IPv6 address: #{@addr}"
+      raise InvalidAddressError, "not an IPv6 address: #{to_s}"
     end
     return _reverse + ".ip6.arpa"
   end
@@ -421,7 +421,7 @@ def ip6_arpa
   # Returns a string for DNS reverse lookup compatible with RFC1886.
   def ip6_int
     if !ipv6?
-      raise InvalidAddressError, "not an IPv6 address: #{@addr}"
+      raise InvalidAddressError, "not an IPv6 address: #{to_s}"
     end
     return _reverse + ".ip6.int"
   end
@@ -743,19 +743,19 @@ def in6_addr(left)
       right = ''
     when RE_IPV6ADDRLIKE_COMPRESSED
       if $4
-        left.count(':') <= 6 or raise InvalidAddressError, "invalid address: #{@addr}"
+        left.count(':') <= 6 or raise InvalidAddressError, "invalid address: #{left}"
         addr = in_addr($~[4,4])
         left = $1
         right = $3 + '0:0'
       else
         left.count(':') <= ($1.empty? || $2.empty? ? 8 : 7) or
-          raise InvalidAddressError, "invalid address: #{@addr}"
+          raise InvalidAddressError, "invalid address: #{left}"
         left = $1
         right = $2
         addr = 0
       end
     else
-      raise InvalidAddressError, "invalid address: #{@addr}"
+      raise InvalidAddressError, "invalid address: #{left}"
     end
     l = left.split(':')
     r = right.split(':')
diff --git a/test/test_ipaddr.rb b/test/test_ipaddr.rb
index 005927c..4b7229f 100644
--- a/test/test_ipaddr.rb
+++ b/test/test_ipaddr.rb
@@ -207,6 +207,15 @@ def test_ipv4_compat
     assert_equal(112, b.prefix)
   end
 
+  def test_ipv4_compat_with_error_message
+    e = assert_raise(IPAddr::InvalidAddressError) do
+      assert_warning(/obsolete/) {
+        IPAddr.new('2001:db8::').ipv4_compat
+      }
+    end
+    assert_equal('not an IPv4 address: 2001:db8::', e.message)
+  end
+
   def test_ipv4_mapped
     a = IPAddr.new("::ffff:192.168.1.2")
     assert_equal("::ffff:192.168.1.2", a.to_s)
@@ -224,6 +233,13 @@ def test_ipv4_mapped
     assert_equal(Socket::AF_INET6, b.family)
   end
 
+  def test_ipv4_mapped_with_error_message
+    e = assert_raise(IPAddr::InvalidAddressError) do
+      IPAddr.new('2001:db8::').ipv4_mapped
+    end
+    assert_equal('not an IPv4 address: 2001:db8::', e.message)
+  end
+
   def test_reverse
     assert_equal("f.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.2.0.0.0.5.0.5.0.e.f.f.3.ip6.arpa", IPAddr.new("3ffe:505:2::f").reverse)
     assert_equal("1.2.168.192.in-addr.arpa", IPAddr.new("192.168.2.1").reverse)
@@ -231,16 +247,18 @@ def test_reverse
 
   def test_ip6_arpa
     assert_equal("f.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.2.0.0.0.5.0.5.0.e.f.f.3.ip6.arpa", IPAddr.new("3ffe:505:2::f").ip6_arpa)
-    assert_raise(IPAddr::InvalidAddressError) {
+    e = assert_raise(IPAddr::InvalidAddressError) {
       IPAddr.new("192.168.2.1").ip6_arpa
     }
+    assert_equal('not an IPv6 address: 192.168.2.1', e.message)
   end
 
   def test_ip6_int
     assert_equal("f.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.2.0.0.0.5.0.5.0.e.f.f.3.ip6.int", IPAddr.new("3ffe:505:2::f").ip6_int)
-    assert_raise(IPAddr::InvalidAddressError) {
+    e = assert_raise(IPAddr::InvalidAddressError) {
       IPAddr.new("192.168.2.1").ip6_int
     }
+    assert_equal('not an IPv6 address: 192.168.2.1', e.message)
   end
 
   def test_prefix_writer
@@ -631,5 +649,10 @@ def test_raises_invalid_address_error_with_error_message
       IPAddr.new('192.168.01.100')
     end
     assert_equal('zero-filled number in IPv4 address is ambiguous: 192.168.01.100', e.message)
+
+    e = assert_raise(IPAddr::InvalidAddressError) do
+      IPAddr.new('INVALID')
+    end
+    assert_equal('invalid address: INVALID', e.message)
   end
 end