diff --git a/src/file_event_publisher.rs b/src/file_event_publisher.rs
index d017066..0214a83 100644
--- a/src/file_event_publisher.rs
+++ b/src/file_event_publisher.rs
@@ -24,7 +24,7 @@ pub struct FileEventPublisher {
 
 impl FileEventPublisher {
     pub async fn connect(relay_config: &RelayConfig) -> Result<Self, HasheusError> {
-        let client = Client::default();
+        let client = relay_connector::build_client();
         let relay_urls = relay_connector::connect_all(&client, &relay_config.file_relay_urls).await;
 
         if relay_urls.is_empty() {
diff --git a/src/profile_fetcher.rs b/src/profile_fetcher.rs
index 58098f2..5da21d0 100644
--- a/src/profile_fetcher.rs
+++ b/src/profile_fetcher.rs
@@ -11,7 +11,7 @@ const PROFILE_TIMEOUT: Duration = Duration::from_secs(3);
 // the newest profile of the user that the relays return in time. each relay is
 // asked on its own, so one that's slow to connect doesn't hide another's answer.
 pub async fn fetch(public_key: PublicKey, relay_urls: &[RelayUrl]) -> Option<Event> {
-    let client = Client::default();
+    let client = relay_connector::build_client();
     let filter = Filter::new()
         .kind(Kind::Metadata)
         .author(public_key)
@@ -56,7 +56,7 @@ pub async fn fetch(public_key: PublicKey, relay_urls: &[RelayUrl]) -> Option<Eve
 mod tests {
     use super::*;
     use crate::test_event_builders::build_profile;
-    use crate::test_relays::{DEAD_RELAY_URL, relay_url, run_relay};
+    use crate::test_relays::{DEAD_RELAY_URL, relay_url, run_mismatching_relay, run_relay};
 
     #[tokio::test]
     async fn fetches_the_newest_profile() {
@@ -69,6 +69,16 @@ mod tests {
         assert_eq!(profile, Some(newer));
     }
 
+    #[tokio::test]
+    async fn ignores_events_a_relay_sends_that_werent_asked_for() {
+        let (_relay, url) = run_mismatching_relay().await;
+
+        assert_eq!(
+            fetch(Keys::generate().public_key(), &[relay_url(&url)]).await,
+            None
+        );
+    }
+
     #[tokio::test]
     async fn has_none_without_a_profile() {
         let (_relay, url) = run_relay(&[build_profile(&Keys::generate(), 1, "someone")]).await;
diff --git a/src/relay_connector.rs b/src/relay_connector.rs
index 199c17b..1968871 100644
--- a/src/relay_connector.rs
+++ b/src/relay_connector.rs
@@ -4,6 +4,12 @@ use tokio::task::JoinSet;
 
 const CONNECT_TIMEOUT: Duration = Duration::from_secs(10);
 
+// like the web page, an event that doesn't match what was asked for is dropped,
+// so a relay can't pass off another file's verification as this file's.
+pub fn build_client() -> Client {
+    Client::builder().verify_subscriptions(true).build()
+}
+
 // a relay that fails to connect isn't retried, so callers only use the ones
 // that connect.
 pub async fn connect(client: &Client, url: &RelayUrl) -> Option<Relay> {
diff --git a/src/test_relays.rs b/src/test_relays.rs
index a396bc3..2e945ba 100644
--- a/src/test_relays.rs
+++ b/src/test_relays.rs
@@ -2,8 +2,9 @@ use crate::relay_config::RelayConfig;
 use nostr_sdk::prelude::*;
 use std::time::Duration;
 
-// relays for tests: one running in the test process, seeded with events, and
-// one that can't be reached.
+// relays for tests: one running in the test process, seeded with events, one
+// that answers with events that weren't asked for, and one that can't be
+// reached.
 
 // nothing listens on port 1, so connecting fails right away.
 pub const DEAD_RELAY_URL: &str = "ws://127.0.0.1:1";
@@ -27,6 +28,19 @@ pub async fn run_relay(events: &[Event]) -> (MockRelay, String) {
     (relay, url.to_string())
 }
 
+// a relay that answers every request with events that don't match it.
+pub async fn run_mismatching_relay() -> (MockRelay, String) {
+    let relay = MockRelay::run_with_opts(LocalRelayTestOptions {
+        unresponsive_connection: None,
+        send_random_events: true,
+    })
+    .await
+    .unwrap();
+    let url = relay.url().await;
+
+    (relay, url.to_string())
+}
+
 pub fn relay_url(url: &str) -> RelayUrl {
     RelayUrl::parse(url).unwrap()
 }
diff --git a/src/verification_fetcher.rs b/src/verification_fetcher.rs
index 9258db3..1cfed08 100644
--- a/src/verification_fetcher.rs
+++ b/src/verification_fetcher.rs
@@ -188,7 +188,7 @@ async fn coordinate(
     sender: mpsc::Sender<Result<Update, HasheusError>>,
 ) {
     // the client shuts its relays down when dropped, so it's held until the end.
-    let client = Client::default();
+    let client = relay_connector::build_client();
     let mut progress = Progress::new(&stages_by_url, user_requirement);
     let mut has_loaded = false;
     let mut has_found_user_profile = false;
@@ -395,7 +395,9 @@ mod tests {
     use crate::test_event_builders::{
         HASH, build_event, build_file_event, build_follow_list, build_profile,
     };
-    use crate::test_relays::{DEAD_RELAY_URL, build_relay_config, relay_url, run_relay};
+    use crate::test_relays::{
+        DEAD_RELAY_URL, build_relay_config, relay_url, run_mismatching_relay, run_relay,
+    };
 
     mod group_stages_by_url {
         use super::*;
@@ -634,6 +636,17 @@ mod tests {
             assert_eq!(received, [Received::Loaded]);
         }
 
+        #[tokio::test]
+        async fn ignores_events_a_relay_sends_that_werent_asked_for() {
+            let (_relay, url) = run_mismatching_relay().await;
+
+            let received = fetch_all(None, build_relay_config(&[&url], &[&url]))
+                .await
+                .unwrap();
+
+            assert_eq!(received, [Received::Loaded]);
+        }
+
         #[tokio::test]
         async fn finishes_with_a_repeated_relay_url() {
             let alice = Keys::generate();