diff --git a/cozo-core/src/storage/rocks.rs b/cozo-core/src/storage/rocks.rs
index d5414600..756e8594 100644
--- a/cozo-core/src/storage/rocks.rs
+++ b/cozo-core/src/storage/rocks.rs
@@ -154,6 +154,8 @@ pub struct RocksDbTx {
     db_tx: Tx,
 }
 
+unsafe impl Sync for RocksDbTx {}
+
 impl<'s> StoreTx<'s> for RocksDbTx {
     #[inline]
     fn get(&self, key: &[u8], for_update: bool) -> Result<Option<Vec<u8>>> {
diff --git a/cozo-core/src/storage/sqlite.rs b/cozo-core/src/storage/sqlite.rs
index 83d779b8..22472051 100644
--- a/cozo-core/src/storage/sqlite.rs
+++ b/cozo-core/src/storage/sqlite.rs
@@ -6,13 +6,12 @@
  * You can obtain one at https://mozilla.org/MPL/2.0/.
  */
 
-use std::cell::RefCell;
 use std::sync::{Arc, Mutex, RwLock, RwLockReadGuard, RwLockWriteGuard};
 
 use ::sqlite::Connection;
 use either::{Either, Left, Right};
 use miette::{bail, miette, IntoDiagnostic, Result};
-use sqlite::{State, Statement};
+use sqlite::{ConnectionWithFullMutex, State, Statement};
 
 use crate::data::tuple::{check_key_for_validity, Tuple};
 use crate::data::value::ValidityTs;
@@ -25,7 +24,7 @@ use crate::utils::swap_option_result;
 pub struct SqliteStorage {
     lock: Arc<RwLock<()>>,
     name: String,
-    pool: Arc<Mutex<Vec<Connection>>>,
+    pool: Arc<Mutex<Vec<ConnectionWithFullMutex>>>,
 }
 
 /// Create a sqlite backed database.
@@ -40,7 +39,7 @@ pub fn new_cozo_sqlite(path: String) -> Result<crate::Db<SqliteStorage>> {
     if path.is_empty() {
         bail!("empty path for sqlite storage")
     }
-    let conn = sqlite::open(&path).into_diagnostic()?;
+    let conn = Connection::open_with_full_mutex(&path).into_diagnostic()?;
     let query = r#"
         create table if not exists cozo
         (
@@ -67,7 +66,7 @@ impl<'s> Storage<'s> for SqliteStorage {
     fn transact(&'s self, write: bool) -> Result<Self::Tx> {
         let conn = {
             match self.pool.lock().unwrap().pop() {
-                None => sqlite::open(&self.name).into_diagnostic()?,
+                None => Connection::open_with_full_mutex(&self.name).into_diagnostic()?,
                 Some(conn) => conn,
             }
         };
@@ -85,10 +84,10 @@ impl<'s> Storage<'s> for SqliteStorage {
             storage: self,
             conn: Some(conn),
             stmts: [
-                RefCell::new(None),
-                RefCell::new(None),
-                RefCell::new(None),
-                RefCell::new(None),
+                Mutex::new(None),
+                Mutex::new(None),
+                Mutex::new(None),
+                Mutex::new(None),
             ],
             committed: false,
         })
@@ -141,11 +140,13 @@ impl<'s> Storage<'s> for SqliteStorage {
 pub struct SqliteTx<'a> {
     lock: Either<RwLockReadGuard<'a, ()>, RwLockWriteGuard<'a, ()>>,
     storage: &'a SqliteStorage,
-    conn: Option<Connection>,
-    stmts: [RefCell<Option<Statement<'a>>>; N_CACHED_QUERIES],
+    conn: Option<ConnectionWithFullMutex>,
+    stmts: [Mutex<Option<Statement<'a>>>; N_CACHED_QUERIES],
     committed: bool,
 }
 
+unsafe impl Sync for SqliteTx<'_> {}
+
 const N_QUERIES: usize = 6;
 const N_CACHED_QUERIES: usize = 4;
 const QUERIES: [&str; N_QUERIES] = [
@@ -180,7 +181,7 @@ impl Drop for SqliteTx<'_> {
 
 impl<'s> SqliteTx<'s> {
     fn ensure_stmt(&self, idx: usize) {
-        let mut stmt = self.stmts[idx].borrow_mut();
+        let mut stmt = self.stmts[idx].lock().unwrap();
         if stmt.is_none() {
             let query = QUERIES[idx];
             let prepared = self.conn.as_ref().unwrap().prepare(query).unwrap();
@@ -198,7 +199,7 @@ impl<'s> SqliteTx<'s> {
 impl<'s> StoreTx<'s> for SqliteTx<'s> {
     fn get(&self, key: &[u8], _for_update: bool) -> Result<Option<Vec<u8>>> {
         self.ensure_stmt(GET_QUERY);
-        let mut statement = self.stmts[GET_QUERY].borrow_mut();
+        let mut statement = self.stmts[GET_QUERY].lock().unwrap();
         let statement = statement.as_mut().unwrap();
         statement.reset().unwrap();
 
@@ -214,7 +215,7 @@ impl<'s> StoreTx<'s> for SqliteTx<'s> {
 
     fn put(&mut self, key: &[u8], val: &[u8]) -> Result<()> {
         self.ensure_stmt(PUT_QUERY);
-        let mut statement = self.stmts[PUT_QUERY].borrow_mut();
+        let mut statement = self.stmts[PUT_QUERY].lock().unwrap();
         let statement = statement.as_mut().unwrap();
         statement.reset().unwrap();
 
@@ -226,7 +227,7 @@ impl<'s> StoreTx<'s> for SqliteTx<'s> {
 
     fn del(&mut self, key: &[u8]) -> Result<()> {
         self.ensure_stmt(DEL_QUERY);
-        let mut statement = self.stmts[DEL_QUERY].borrow_mut();
+        let mut statement = self.stmts[DEL_QUERY].lock().unwrap();
         let statement = statement.as_mut().unwrap();
         statement.reset().unwrap();
 
@@ -238,7 +239,7 @@ impl<'s> StoreTx<'s> for SqliteTx<'s> {
 
     fn exists(&self, key: &[u8], _for_update: bool) -> Result<bool> {
         self.ensure_stmt(EXISTS_QUERY);
-        let mut statement = self.stmts[EXISTS_QUERY].borrow_mut();
+        let mut statement = self.stmts[EXISTS_QUERY].lock().unwrap();
         let statement = statement.as_mut().unwrap();
         statement.reset().unwrap();
 
@@ -385,7 +386,7 @@ impl<'l> SkipIter<'l> {
                     if let Some(mut tup) = ret {
                         let v = self.stmt.read::<Vec<u8>, _>(1).unwrap();
                         extend_tuple_from_v(&mut tup, &v);
-                        return Ok(Some(tup))
+                        return Ok(Some(tup));
                     }
                 }
             }
diff --git a/cozo-core/tests/air_routes.rs b/cozo-core/tests/air_routes.rs
index ed2c9d8e..5b5b0c8f 100644
--- a/cozo-core/tests/air_routes.rs
+++ b/cozo-core/tests/air_routes.rs
@@ -193,6 +193,30 @@ fn empty() {
     assert!(res.is_err());
 }
 
+#[test]
+fn parallel_counts() {
+    initialize(&TEST_DB);
+    let res = TEST_DB
+        .run_script(
+            r#"
+        a[count(fr)] := *route{fr}
+        b[count(fr)] := *route{fr}
+        c[count(fr)] := *route{fr}
+        d[count(fr)] := *route{fr}
+        e[count(fr)] := *route{fr}
+        ?[x] := a[a], b[b], c[c], d[d], e[e], x = a + b + c + d + e
+        "#,
+            Default::default(),
+        )
+        .unwrap()
+        .rows
+        .remove(0)
+        .remove(0)
+        .as_i64()
+        .unwrap();
+    assert_eq!(res, 50637 * 5);
+}
+
 #[test]
 fn bfs() {
     initialize(&TEST_DB);