diff --git a/web3_proxy/src/bin/web3_proxy_cli/sentryd/compare.rs b/web3_proxy/src/bin/web3_proxy_cli/sentryd/compare.rs
index 50fcea7a..ada4681e 100644
--- a/web3_proxy/src/bin/web3_proxy_cli/sentryd/compare.rs
+++ b/web3_proxy/src/bin/web3_proxy_cli/sentryd/compare.rs
@@ -1,6 +1,6 @@
 use anyhow::{anyhow, Context};
 use chrono::{DateTime, Utc};
-use ethers::types::{Block, TxHash, H256, U64};
+use ethers::types::{Block, TxHash, H256};
 use futures::{stream::FuturesUnordered, StreamExt};
 use log::{debug, warn};
 use serde::{Deserialize, Serialize};
@@ -34,7 +34,12 @@ impl From<Block<TxHash>> for AbbreviatedBlock {
     }
 }
 
-pub async fn main(rpc: String, others: Vec<String>, max_lag: i64) -> anyhow::Result<()> {
+pub async fn main(
+    rpc: String,
+    others: Vec<String>,
+    max_age: i64,
+    max_lag: i64,
+) -> anyhow::Result<()> {
     let client = reqwest::Client::new();
 
     let block_by_number_request = json!({
@@ -118,7 +123,7 @@ pub async fn main(rpc: String, others: Vec<String>, max_lag: i64) -> anyhow::Res
             .signed_duration_since(newest_other.max(&rpc_block).time)
             .num_seconds();
 
-        match block_age.abs().cmp(&max_lag) {
+        match block_age.abs().cmp(&max_age) {
             std::cmp::Ordering::Less | std::cmp::Ordering::Equal => {}
             std::cmp::Ordering::Greater => match duration_since.cmp(&0) {
                 std::cmp::Ordering::Equal => unimplemented!(),
diff --git a/web3_proxy/src/bin/web3_proxy_cli/sentryd/mod.rs b/web3_proxy/src/bin/web3_proxy_cli/sentryd/mod.rs
index 22b6aab1..51d0df7a 100644
--- a/web3_proxy/src/bin/web3_proxy_cli/sentryd/mod.rs
+++ b/web3_proxy/src/bin/web3_proxy_cli/sentryd/mod.rs
@@ -21,6 +21,10 @@ pub struct SentrydSubCommand {
     /// the main (HTTP only) web3-proxy being checked.
     web3_proxy: String,
 
+    #[argh(option)]
+    /// warning threshold for age of the best known head block
+    max_age: i64,
+
     #[argh(option)]
     /// warning threshold for seconds between the rpc and best other_rpc's head blocks
     max_lag: i64,
@@ -69,6 +73,7 @@ impl SentrydSubCommand {
 
         // compare the main web3-proxy head block to all web3-proxies and rpcs
         {
+            let max_age = self.max_age;
             let max_lag = self.max_lag;
             let rpc = self.web3_proxy.clone();
 
@@ -77,7 +82,7 @@ impl SentrydSubCommand {
             others.extend(self.other_rpc.clone());
 
             let loop_f = a_loop(seconds, log::Level::Error, move || {
-                compare::main(rpc.clone(), others.clone(), max_lag)
+                compare::main(rpc.clone(), others.clone(), max_age, max_lag)
             });
 
             handles.push(tokio::spawn(loop_f));