diff --git a/QueryBuilder/Compilers/Compiler.Conditions.cs b/QueryBuilder/Compilers/Compiler.Conditions.cs
index 6615c246..8fab1fff 100644
--- a/QueryBuilder/Compilers/Compiler.Conditions.cs
+++ b/QueryBuilder/Compilers/Compiler.Conditions.cs
@@ -184,7 +184,7 @@ protected virtual string CompileNestedCondition<Q>(SqlResult ctx, NestedConditio
             return x.IsNot ? $"NOT ({sql})" : $"({sql})";
         }
 
-        protected string CompileTwoColumnsCondition(SqlResult ctx, TwoColumnsCondition clause)
+        protected virtual string CompileTwoColumnsCondition(SqlResult ctx, TwoColumnsCondition clause)
         {
             var op = clause.IsNot ? "NOT " : "";
             return $"{op}{Wrap(clause.First)} {checkOperator(clause.Operator)} {Wrap(clause.Second)}";