diff --git a/Lib/ipaddress.py b/Lib/ipaddress.py
index 909a55d..662d737 100644
--- a/Lib/ipaddress.py
+++ b/Lib/ipaddress.py
@@ -697,8 +697,7 @@
         # dealing with another address
         else:
             # address
-            return (int(self.network_address) <= int(other._ip) <=
-                    int(self.broadcast_address))
+            return other._ip & self.netmask._ip == self.network_address._ip
 
     def overlaps(self, other):
         """Tell if self is partly contained in other."""
diff --git a/Misc/NEWS.d/next/Library/2019-04-15-12-22-09.bpo-25430.7_8kqc.rst b/Misc/NEWS.d/next/Library/2019-04-15-12-22-09.bpo-25430.7_8kqc.rst
new file mode 100644
index 0000000..922bdef
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2019-04-15-12-22-09.bpo-25430.7_8kqc.rst
@@ -0,0 +1 @@
+improve performance of ``IPNetwork.__contains__()``
\ No newline at end of file