diff --git a/Cargo.lock b/Cargo.lock
index 5597022cf7..914d76f4b5 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -4103,6 +4103,8 @@ version = "0.22.0"
 dependencies = [
  "clap 2.33.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.8 (registry+https://github.com/rust-lang/crates.io-index)",
+ "reqwest 0.9.24 (registry+https://github.com/rust-lang/crates.io-index)",
+ "serde_json 1.0.44 (registry+https://github.com/rust-lang/crates.io-index)",
  "solana-clap-utils 0.22.0",
  "solana-client 0.22.0",
  "solana-logger 0.22.0",
diff --git a/programs/vote/src/vote_instruction.rs b/programs/vote/src/vote_instruction.rs
index 0e583a60af..076609f9cc 100644
--- a/programs/vote/src/vote_instruction.rs
+++ b/programs/vote/src/vote_instruction.rs
@@ -103,11 +103,12 @@ pub fn authorize(
 }
 
 pub fn update_node(
-    vote_pubkey: &Pubkey,       // vote account
-    authorized_pubkey: &Pubkey, // currently authorized
+    vote_pubkey: &Pubkey,
+    authorized_voter_pubkey: &Pubkey,
     node_pubkey: &Pubkey,
 ) -> Instruction {
-    let account_metas = vec![AccountMeta::new(*vote_pubkey, false)].with_signer(authorized_pubkey);
+    let account_metas =
+        vec![AccountMeta::new(*vote_pubkey, false)].with_signer(authorized_voter_pubkey);
 
     Instruction::new(
         id(),
diff --git a/watchtower/Cargo.toml b/watchtower/Cargo.toml
index 35fde38bd3..5fcc19a8b5 100644
--- a/watchtower/Cargo.toml
+++ b/watchtower/Cargo.toml
@@ -11,6 +11,8 @@ homepage = "https://solana.com/"
 [dependencies]
 clap = "2.33.0"
 log = "0.4.8"
+reqwest = { version = "0.9.24", default-features = false, features = ["rustls-tls"] }
+serde_json = "1.0"
 solana-clap-utils = { path = "../clap-utils", version = "0.22.0" }
 solana-client = { path = "../client", version = "0.22.0" }
 solana-logger = { path = "../logger", version = "0.22.0" }
diff --git a/watchtower/README.md b/watchtower/README.md
index 1779eb2528..ca20e50f23 100644
--- a/watchtower/README.md
+++ b/watchtower/README.md
@@ -1,7 +1,8 @@
 The `solana-watchtower` program is used to monitor the health of a cluster.  It
 periodically polls the cluster over an RPC API to confirm that the transaction
 count is advancing, new blockhashes are available, and no validators are
-delinquent.  Results are reported as InfluxDB metrics.
+delinquent.  Results are reported as InfluxDB metrics, with an optional
+Slack/Discord push notification on sanity failure.
 
 ### Metrics
 #### `watchtower-sanity`
@@ -14,3 +15,11 @@ the following fields:
 * `test`: name of the sanity test that failed
 * `err`: exact sanity failure message
 
+
+### Sanity failure push notification
+To receive a Slack and/or Discord notification on sanity failure, define one or
+both of these environment variables before running `solana-watchtower`:
+```
+export SLACK_WEBHOOK=...
+export DISCORD_WEBHOOK=...
+```
diff --git a/watchtower/src/main.rs b/watchtower/src/main.rs
index 81aca44669..9ea9d6b28c 100644
--- a/watchtower/src/main.rs
+++ b/watchtower/src/main.rs
@@ -1,5 +1,8 @@
 //! A command-line executable for monitoring the health of a cluster
 
+mod notifier;
+
+use crate::notifier::Notifier;
 use clap::{crate_description, crate_name, value_t_or_exit, App, Arg};
 use log::*;
 use solana_clap_utils::input_validators::is_url;
@@ -38,6 +41,7 @@ fn main() -> Result<(), Box<dyn error::Error>> {
 
     let rpc_client = RpcClient::new(json_rpc_url.to_string());
 
+    let notifier = Notifier::new();
     let mut last_transaction_count = 0;
     loop {
         let ok = rpc_client
@@ -111,6 +115,9 @@ fn main() -> Result<(), Box<dyn error::Error>> {
                 });
 
         datapoint_info!("watchtower-sanity", ("ok", ok, bool));
+        if !ok {
+            notifier.send("solana-watchtower sanity failure");
+        }
         sleep(interval);
     }
 }
diff --git a/watchtower/src/notifier.rs b/watchtower/src/notifier.rs
new file mode 100644
index 0000000000..fec44fdb65
--- /dev/null
+++ b/watchtower/src/notifier.rs
@@ -0,0 +1,46 @@
+use log::*;
+use reqwest::Client;
+use serde_json::json;
+use std::env;
+
+pub struct Notifier {
+    client: Client,
+    discord_webhook: Option<String>,
+    slack_webhook: Option<String>,
+}
+
+impl Notifier {
+    pub fn new() -> Self {
+        let discord_webhook = env::var("DISCORD_WEBHOOK")
+            .map_err(|_| {
+                warn!("Discord notifications disabled");
+            })
+            .ok();
+        let slack_webhook = env::var("SLACK_WEBHOOK")
+            .map_err(|_| {
+                warn!("Slack notifications disabled");
+            })
+            .ok();
+        Notifier {
+            client: Client::new(),
+            discord_webhook,
+            slack_webhook,
+        }
+    }
+
+    pub fn send(&self, msg: &str) {
+        if let Some(webhook) = &self.discord_webhook {
+            let data = json!({ "content": msg });
+            if let Err(err) = self.client.post(webhook).json(&data).send() {
+                warn!("Failed to send Discord message: {:?}", err);
+            }
+        }
+
+        if let Some(webhook) = &self.slack_webhook {
+            let data = json!({ "text": msg });
+            if let Err(err) = self.client.post(webhook).json(&data).send() {
+                warn!("Failed to send Slack message: {:?}", err);
+            }
+        }
+    }
+}