diff --git a/src/Carbunql/IQuerySource.cs b/src/Carbunql/IQuerySource.cs
index c2d0d71b..26f937ad 100644
--- a/src/Carbunql/IQuerySource.cs
+++ b/src/Carbunql/IQuerySource.cs
@@ -1,5 +1,6 @@
 using Carbunql.Building;
 using Carbunql.Clauses;
+using Carbunql.Extensions;
 using Carbunql.Tables;
 
 namespace Carbunql;