diff --git a/crates/cli/src/commands/syn2mas.rs b/crates/cli/src/commands/syn2mas.rs
index b5d7b4b7b..0d1b2dc2c 100644
--- a/crates/cli/src/commands/syn2mas.rs
+++ b/crates/cli/src/commands/syn2mas.rs
@@ -15,7 +15,7 @@ use sqlx::{Connection, Either, PgConnection, postgres::PgConnectOptions, types::
 use syn2mas::{LockedMasDatabase, MasWriter, SynapseReader, synapse_config};
 use tracing::{Instrument, error, info_span, warn};
 
-use crate::util::database_connection_from_config;
+use crate::util::{DatabaseConnectOptions, database_connection_from_config_with_options};
 
 /// The exit code used by `syn2mas check` and `syn2mas migrate` when there are
 /// errors preventing migration.
@@ -114,7 +114,13 @@ impl Options {
 
         let config = DatabaseConfig::extract_or_default(figment)?;
 
-        let mut mas_connection = database_connection_from_config(&config).await?;
+        let mut mas_connection = database_connection_from_config_with_options(
+            &config,
+            &DatabaseConnectOptions {
+                log_slow_statements: false,
+            },
+        )
+        .await?;
 
         MIGRATOR
             .run(&mut mas_connection)
@@ -225,7 +231,15 @@ impl Options {
                 let reader = SynapseReader::new(&mut syn_conn, true).await?;
                 let mut writer_mas_connections = Vec::with_capacity(NUM_WRITER_CONNECTIONS);
                 for _ in 0..NUM_WRITER_CONNECTIONS {
-                    writer_mas_connections.push(database_connection_from_config(&config).await?);
+                    writer_mas_connections.push(
+                        database_connection_from_config_with_options(
+                            &config,
+                            &DatabaseConnectOptions {
+                                log_slow_statements: false,
+                            },
+                        )
+                        .await?,
+                    );
                 }
                 let writer = MasWriter::new(mas_connection, writer_mas_connections).await?;
 
diff --git a/crates/cli/src/util.rs b/crates/cli/src/util.rs
index 27c23eeb5..2766e5bbb 100644
--- a/crates/cli/src/util.rs
+++ b/crates/cli/src/util.rs
@@ -231,6 +231,7 @@ pub async fn templates_from_config(
 
 fn database_connect_options_from_config(
     config: &DatabaseConfig,
+    opts: &DatabaseConnectOptions,
 ) -> Result<PgConnectOptions, anyhow::Error> {
     let options = if let Some(uri) = config.uri.as_deref() {
         uri.parse()
@@ -315,9 +316,11 @@ fn database_connect_options_from_config(
         None => options,
     };
 
-    let options = options
-        .log_statements(LevelFilter::Debug)
-        .log_slow_statements(LevelFilter::Warn, Duration::from_millis(100));
+    let mut options = options.log_statements(LevelFilter::Debug);
+
+    if opts.log_slow_statements {
+        options = options.log_slow_statements(LevelFilter::Warn, Duration::from_millis(100));
+    }
 
     Ok(options)
 }
@@ -325,7 +328,7 @@ fn database_connect_options_from_config(
 /// Create a database connection pool from the configuration
 #[tracing::instrument(name = "db.connect", skip_all, err(Debug))]
 pub async fn database_pool_from_config(config: &DatabaseConfig) -> Result<PgPool, anyhow::Error> {
-    let options = database_connect_options_from_config(config)?;
+    let options = database_connect_options_from_config(config, &DatabaseConnectOptions::default())?;
     PgPoolOptions::new()
         .max_connections(config.max_connections.into())
         .min_connections(config.min_connections)
@@ -337,12 +340,37 @@ pub async fn database_pool_from_config(config: &DatabaseConfig) -> Result<PgPool
         .context("could not connect to the database")
 }
 
+pub struct DatabaseConnectOptions {
+    pub log_slow_statements: bool,
+}
+
+impl Default for DatabaseConnectOptions {
+    fn default() -> Self {
+        Self {
+            log_slow_statements: true,
+        }
+    }
+}
+
 /// Create a single database connection from the configuration
 #[tracing::instrument(name = "db.connect", skip_all, err(Debug))]
 pub async fn database_connection_from_config(
     config: &DatabaseConfig,
 ) -> Result<PgConnection, anyhow::Error> {
-    database_connect_options_from_config(config)?
+    database_connect_options_from_config(config, &DatabaseConnectOptions::default())?
+        .connect()
+        .await
+        .context("could not connect to the database")
+}
+
+/// Create a single database connection from the configuration,
+/// with specific options.
+#[tracing::instrument(name = "db.connect", skip_all, err(Debug))]
+pub async fn database_connection_from_config_with_options(
+    config: &DatabaseConfig,
+    options: &DatabaseConnectOptions,
+) -> Result<PgConnection, anyhow::Error> {
+    database_connect_options_from_config(config, options)?
         .connect()
         .await
         .context("could not connect to the database")
diff --git a/crates/syn2mas/src/synapse_reader/mod.rs b/crates/syn2mas/src/synapse_reader/mod.rs
index 63d8386d9..7bce256d9 100644
--- a/crates/syn2mas/src/synapse_reader/mod.rs
+++ b/crates/syn2mas/src/synapse_reader/mod.rs
@@ -449,7 +449,7 @@ impl<'conn> SynapseReader<'conn> {
             INNER JOIN devices USING (user_id, device_id)
             WHERE at0.puppets_user_id IS NULL AND at0.refresh_token_id IS NULL
 
-            UNION
+            UNION ALL
 
             SELECT
               at0.user_id, at0.device_id, at0.token, at0.valid_until_ms, at0.last_validated
@@ -478,7 +478,7 @@ impl<'conn> SynapseReader<'conn> {
             SELECT
               rt0.user_id, rt0.device_id, at0.token AS access_token, rt0.token AS refresh_token, at0.valid_until_ms, at0.last_validated
             FROM refresh_tokens rt0
-            INNER JOIN devices USING (device_id)
+            INNER JOIN devices USING (user_id, device_id)
             INNER JOIN access_tokens at0 ON at0.refresh_token_id = rt0.id AND at0.user_id = rt0.user_id AND at0.device_id = rt0.device_id
             LEFT JOIN access_tokens at1 ON at1.refresh_token_id = rt0.next_token_id
             WHERE NOT at1.used OR at1.used IS NULL
@@ -505,7 +505,6 @@ mod test {
         },
     };
 
-    // TODO test me
     static MIGRATOR: Migrator = sqlx::migrate!("./test_synapse_migrations");
 
     #[sqlx::test(migrator = "MIGRATOR", fixtures("user_alice"))]