diff --git a/datafusion/functions-aggregate/src/first_last.rs b/datafusion/functions-aggregate/src/first_last.rs
index 8c17854a8aae..23fb11a379c9 100644
--- a/datafusion/functions-aggregate/src/first_last.rs
+++ b/datafusion/functions-aggregate/src/first_last.rs
@@ -405,11 +405,7 @@ impl FirstValuePhysicalExpr {
     }
 
     pub fn convert_to_last(self) -> LastValuePhysicalExpr {
-        let mut name = if self.name.starts_with("FIRST") {
-            format!("LAST{}", &self.name[5..])
-        } else {
-            format!("LAST_VALUE({})", self.expr)
-        };
+        let mut name = format!("LAST{}", &self.name[5..]);
         replace_order_by_clause(&mut name);
 
         let FirstValuePhysicalExpr {
@@ -585,11 +581,7 @@ impl LastValuePhysicalExpr {
     }
 
     pub fn convert_to_first(self) -> FirstValuePhysicalExpr {
-        let mut name = if self.name.starts_with("LAST") {
-            format!("FIRST{}", &self.name[4..])
-        } else {
-            format!("FIRST_VALUE({})", self.expr)
-        };
+        let mut name = format!("FIRST{}", &self.name[4..]);
         replace_order_by_clause(&mut name);
 
         let LastValuePhysicalExpr {
diff --git a/datafusion/physical-expr/src/equivalence/projection.rs b/datafusion/physical-expr/src/equivalence/projection.rs
index b1f30a39e71c..ea852c0d0bf6 100644
--- a/datafusion/physical-expr/src/equivalence/projection.rs
+++ b/datafusion/physical-expr/src/equivalence/projection.rs
@@ -20,7 +20,7 @@ use std::sync::Arc;
 use arrow::datatypes::SchemaRef;
 
 use datafusion_common::tree_node::{Transformed, TransformedResult, TreeNode};
-use datafusion_common::{DataFusionError, Result};
+use datafusion_common::{internal_err, Result};
 
 use crate::expressions::Column;
 use crate::PhysicalExpr;
@@ -68,8 +68,9 @@ impl ProjectionMapping {
                             let idx = col.index();
                             let matching_input_field = input_schema.field(idx);
                             if col.name() != matching_input_field.name() {
-                                return Err(DataFusionError::Internal(format!("Input field name {} does not match with the projection expression {}",matching_input_field.name(),col.name())));
-                            }
+                                return internal_err!("Input field name {} does not match with the projection expression {}",
+                                    matching_input_field.name(),col.name())
+                                }
                             let matching_input_column =
                                 Column::new(matching_input_field.name(), idx);
                             Ok(Transformed::yes(Arc::new(matching_input_column)))