diff --git a/db/src/db.rs b/db/src/db.rs
index 8b430548..ccdfc7d9 100644
--- a/db/src/db.rs
+++ b/db/src/db.rs
@@ -69,12 +69,19 @@ pub fn new_connection<T>(uri: T) -> rusqlite::Result<rusqlite::Connection> where
         _ => rusqlite::Connection::open(uri)?,
     };
 
+    /// See https://github.com/mozilla/mentat/issues/505 for details on temp_store
+    /// pragma and how it might interact together with consumers such as Firefox.
+    /// temp_store=2 is currently present to force SQLite to store temp files in memory.
+    /// Some of the platforms we support do not have a tmp partition (e.g. Android)
+    /// necessary to store temp files on disk. Ideally, consumers should be able to
+    /// override this behaviour (see issue 505).
     conn.execute_batch("
         PRAGMA page_size=32768;
         PRAGMA journal_mode=wal;
         PRAGMA wal_autocheckpoint=32;
         PRAGMA journal_size_limit=3145728;
         PRAGMA foreign_keys=ON;
+        PRAGMA temp_store=2;
     ")?;
 
     Ok(conn)