diff --git a/core/src/main/java/com/google/bitcoin/params/TestNet3Params.java b/core/src/main/java/com/google/bitcoin/params/TestNet3Params.java
index 0b1bdf10..87896ab6 100644
--- a/core/src/main/java/com/google/bitcoin/params/TestNet3Params.java
+++ b/core/src/main/java/com/google/bitcoin/params/TestNet3Params.java
@@ -18,6 +18,7 @@ package com.google.bitcoin.params;
 
 import com.google.bitcoin.core.NetworkParameters;
 import com.google.bitcoin.core.Utils;
+import org.spongycastle.util.encoders.Hex;
 
 import static com.google.common.base.Preconditions.checkState;
 
@@ -45,6 +46,7 @@ public class TestNet3Params extends NetworkParameters {
         subsidyDecreaseBlockCount = 210000;
         String genesisHash = genesisBlock.getHashAsString();
         checkState(genesisHash.equals("000000000933ea01ad0ee984209779baaec3ced90fa3f408719526f8d77f4943"));
+        alertSigningKey = Hex.decode("04302390343f91cc401d56d68b123028bf52e5fca1939df127f63c6467cdf9c8e2c14b61104cf817d0b780da337893ecc4aaff1309e536162dabbdb45200ca2b0a");
 
         dnsSeeds = new String[] {
                 "testnet-seed.bitcoin.petertodd.org",