diff --git a/src/ipv4.rs b/src/ipv4.rs
index d9b1db2..06726ff 100644
--- a/src/ipv4.rs
+++ b/src/ipv4.rs
@@ -80,7 +80,7 @@ impl Ipv4Network {
 
     /// Checks if the given `Ipv4Network` is a subnet of the other.
     pub fn is_subnet_of(self, other: Ipv4Network) -> bool {
-        other.ip() <= self.ip() && other.broadcast() >= self.broadcast()
+        other.network() <= self.network() && other.broadcast() >= self.broadcast()
     }
 
     /// Checks if the given `Ipv4Network` is a supernet of the other.
diff --git a/src/ipv6.rs b/src/ipv6.rs
index 129edab..f3a21e7 100644
--- a/src/ipv6.rs
+++ b/src/ipv6.rs
@@ -122,7 +122,7 @@ impl Ipv6Network {
 
     /// Checks if the given `Ipv6Network` is a subnet of the other.
     pub fn is_subnet_of(self, other: Ipv6Network) -> bool {
-        other.ip() <= self.ip() && other.broadcast() >= self.broadcast()
+        other.network() <= self.network() && other.broadcast() >= self.broadcast()
     }
 
     /// Checks if the given `Ipv6Network` is a supernet of the other.