diff --git a/src/db/mod.rs b/src/db/mod.rs
index 1598a594..d5f59145 100644
--- a/src/db/mod.rs
+++ b/src/db/mod.rs
@@ -118,6 +118,7 @@ fn upgrade(db: &Connection, mut version: u16) -> Result<(), Error> {
     apply_sql!(db, version, 10, "schema10.sql");
     apply_sql!(db, version, 11, "schema11.sql");
     apply_sql!(db, version, 12, "schema12.sql");
+    apply_sql!(db, version, 13, "schema13.sql");
     tracing::info!("Database is at version {}", version);
     Ok(())
 }
diff --git a/src/db/schema13.sql b/src/db/schema13.sql
new file mode 100644
index 00000000..e411b5eb
--- /dev/null
+++ b/src/db/schema13.sql
@@ -0,0 +1,7 @@
+
+-- I tried to merge records with relays ending in '/' to records where they didn't, but SQLITE makes it very hard to update joins (you can't do it directly, and I think the join ON clause is too complex to use EXISTS tricks).
+-- So I'm just going to delete such records.  The data lost is statistical and not critical.
+
+DELETE FROM event_seen WHERE SUBSTR(relay, LENGTH(relay), 1) == '/';
+DELETE FROM person_relay WHERE SUBSTR(relay, LENGTH(relay), 1) == '/';
+DELETE FROM relay WHERE SUBSTR(url, LENGTH(url), 1) == '/';