diff --git a/router/src/gossip/anti_entropy/mst/mod.rs b/router/src/gossip/anti_entropy/mst/mod.rs
index c997f4c57f6..130eee090b8 100644
--- a/router/src/gossip/anti_entropy/mst/mod.rs
+++ b/router/src/gossip/anti_entropy/mst/mod.rs
@@ -8,7 +8,7 @@ pub mod merkle;
 
 #[cfg(test)]
 mod tests {
-    use std::sync::Arc;
+    use std::{sync::Arc, time::Duration};
 
     use crate::{
         gossip::anti_entropy::{
@@ -20,6 +20,7 @@ mod tests {
 
     use data_types::NamespaceSchema;
     use proptest::prelude::*;
+    use test_helpers::timeout::FutureTimeout;
 
     use super::handle::AntiEntropyHandle;
 
@@ -67,7 +68,9 @@ mod tests {
                     ns_b.put_schema(name, update);
 
                     // Invariant: after applying the same update, the content hashes
-                    // MUST match (even if this update was a no-op / not an update)
+                    // MUST match (even if this update was a no-op / not an
+                    // update)
+                    wait_for_convergence(&handle_a, &handle_b).await;
                     assert_eq!(handle_a.content_hash().await, handle_b.content_hash().await);
                     // Invariant: and the same serialised snapshot content
                     assert_eq!(handle_a.snapshot().await, handle_b.snapshot().await);
@@ -89,6 +92,7 @@ mod tests {
                 // Invariant: applying the update to the other cache converges their
                 // content hashes.
                 ns_b.put_schema(name, last_update);
+                wait_for_convergence(&handle_a, &handle_b).await;
                 assert_eq!(handle_a.content_hash().await, handle_b.content_hash().await);
                 // Invariant: and the serialised snapshot content converges
                 assert_eq!(handle_a.snapshot().await, handle_b.snapshot().await);
@@ -198,4 +202,17 @@ mod tests {
             }
         }
     }
+
+    async fn wait_for_convergence(mst_a: &AntiEntropyHandle, mst_b: &AntiEntropyHandle) {
+        async {
+            loop {
+                if mst_a.content_hash().await == mst_b.content_hash().await {
+                    break;
+                }
+                tokio::time::sleep(Duration::from_millis(50)).await;
+            }
+        }
+        .with_timeout_panic(Duration::from_secs(5))
+        .await
+    }
 }