diff --git a/src/planner/mod.rs b/src/planner/mod.rs
index c883bea..829dce4 100644
--- a/src/planner/mod.rs
+++ b/src/planner/mod.rs
@@ -31,10 +31,11 @@ pub struct DefaultQueryPlanner;
 impl DefaultQueryPlanner {
     fn physical_plan_projection(&self, projection: &Projection) -> Result<Arc<dyn PhysicalPlan>> {
         let physical_plan = self.create_physical_plan(&projection.input)?;
+        let schema = physical_plan.schema();
         let exprs = projection
             .exprs
             .iter()
-            .map(|e| self.create_physical_expr(&projection.schema, e))
+            .map(|e| self.create_physical_expr(&schema, e))
             .collect::<Result<Vec<_>>>()?;
         Ok(Arc::new(physical::plan::Projection::new(
             projection.schema.clone(),