diff --git a/src/database.js b/src/database.js
index 6856f353b..0e3f6e1eb 100644
--- a/src/database.js
+++ b/src/database.js
@@ -126,6 +126,8 @@ function clear(callback) {
 function beginTransaction(callback) {
     assert.strictEqual(typeof callback, 'function');
 
+    if (gConnectionPool === null) return callback(new Error('No database connection pool.'));
+
     gConnectionPool.getConnection(function (error, connection) {
         if (error) return callback(error);