diff --git a/core/java/android/net/RouteInfo.java b/core/java/android/net/RouteInfo.java
index ea6002c..67bad53 100644
--- a/core/java/android/net/RouteInfo.java
+++ b/core/java/android/net/RouteInfo.java
@@ -104,6 +104,11 @@
      */
     private final int mType;
 
+    /**
+     * The maximum transmission unit size for this route.
+     */
+    private final int mMtu;
+
     // Derived data members.
     // TODO: remove these.
     @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.P, trackingBug = 115609023)
@@ -132,6 +137,31 @@
     @TestApi
     public RouteInfo(@Nullable IpPrefix destination, @Nullable InetAddress gateway,
             @Nullable String iface, @RouteType int type) {
+        this(destination, gateway, iface, type, 0);
+    }
+
+    /**
+     * Constructs a RouteInfo object.
+     *
+     * If destination is null, then gateway must be specified and the
+     * constructed route is either the IPv4 default route <code>0.0.0.0</code>
+     * if the gateway is an instance of {@link Inet4Address}, or the IPv6 default
+     * route <code>::/0</code> if gateway is an instance of
+     * {@link Inet6Address}.
+     * <p>
+     * destination and gateway may not both be null.
+     *
+     * @param destination the destination prefix
+     * @param gateway the IP address to route packets through
+     * @param iface the interface name to send packets on
+     * @param type the type of this route
+     * @param mtu the maximum transmission unit size for this route
+     *
+     * @hide
+     */
+    @SystemApi
+    public RouteInfo(@Nullable IpPrefix destination, @Nullable InetAddress gateway,
+            @Nullable String iface, @RouteType int type, int mtu) {
         switch (type) {
             case RTN_UNICAST:
             case RTN_UNREACHABLE:
@@ -161,7 +191,7 @@
             } else {
                 // no destination, no gateway. invalid.
                 throw new IllegalArgumentException("Invalid arguments passed in: " + gateway + "," +
-                                                   destination);
+                        destination);
             }
         }
         // TODO: set mGateway to null if there is no gateway. This is more correct, saves space, and
@@ -176,10 +206,10 @@
         }
         mHasGateway = (!gateway.isAnyLocalAddress());
 
-        if ((destination.getAddress() instanceof Inet4Address &&
-                 (gateway instanceof Inet4Address == false)) ||
-                (destination.getAddress() instanceof Inet6Address &&
-                 (gateway instanceof Inet6Address == false))) {
+        if ((destination.getAddress() instanceof Inet4Address
+                && !(gateway instanceof Inet4Address))
+                || (destination.getAddress() instanceof Inet6Address
+                && !(gateway instanceof Inet6Address))) {
             throw new IllegalArgumentException("address family mismatch in RouteInfo constructor");
         }
         mDestination = destination;  // IpPrefix objects are immutable.
@@ -187,6 +217,7 @@
         mInterface = iface;          // Strings are immutable.
         mType = type;
         mIsHost = isHost();
+        mMtu = mtu;
     }
 
     /**
@@ -373,6 +404,17 @@
     }
 
     /**
+     * Retrieves the MTU size for this route.
+     *
+     * @return The MTU size, or 0 if it has not been set.
+     * @hide
+     */
+    @SystemApi
+    public int getMtu() {
+        return mMtu;
+    }
+
+    /**
      * Indicates if this route is a default route (ie, has no destination specified).
      *
      * @return {@code true} if the destination has a prefix length of 0.
@@ -476,6 +518,7 @@
                 val += " unknown type " + mType;
             }
         }
+        val += " mtu " + mMtu;
         return val;
     }
 
@@ -493,7 +536,7 @@
         return Objects.equals(mDestination, target.getDestination()) &&
                 Objects.equals(mGateway, target.getGateway()) &&
                 Objects.equals(mInterface, target.getInterface()) &&
-                mType == target.getType();
+                mType == target.getType() && mMtu == target.getMtu();
     }
 
     /**
@@ -503,7 +546,7 @@
         return (mDestination.hashCode() * 41)
                 + (mGateway == null ? 0 :mGateway.hashCode() * 47)
                 + (mInterface == null ? 0 :mInterface.hashCode() * 67)
-                + (mType * 71);
+                + (mType * 71) + (mMtu * 89);
     }
 
     /**
@@ -522,6 +565,7 @@
         dest.writeByteArray(gatewayBytes);
         dest.writeString(mInterface);
         dest.writeInt(mType);
+        dest.writeInt(mMtu);
     }
 
     /**
@@ -540,8 +584,9 @@
 
             String iface = in.readString();
             int type = in.readInt();
+            int mtu = in.readInt();
 
-            return new RouteInfo(dest, gateway, iface, type);
+            return new RouteInfo(dest, gateway, iface, type, mtu);
         }
 
         public RouteInfo[] newArray(int size) {
diff --git a/tests/net/common/java/android/net/RouteInfoTest.java b/tests/net/common/java/android/net/RouteInfoTest.java
index 5ce8436..fe51b3a 100644
--- a/tests/net/common/java/android/net/RouteInfoTest.java
+++ b/tests/net/common/java/android/net/RouteInfoTest.java
@@ -258,6 +258,16 @@
         assertParcelingIsLossless(r);
 
         r = new RouteInfo(Prefix("192.0.2.0/24"), null, "wlan0");
-        assertParcelSane(r, 6);
+        assertParcelSane(r, 7);
+    }
+
+    public void testMtu() {
+        RouteInfo r;
+        r = new RouteInfo(Prefix("0.0.0.0/0"), Address("0.0.0.0"), "wlan0",
+                RouteInfo.RTN_UNICAST, 1500);
+        assertEquals(1500, r.getMtu());
+
+        r = new RouteInfo(Prefix("0.0.0.0/0"), Address("0.0.0.0"), "wlan0");
+        assertEquals(0, r.getMtu());
     }
 }