diff --git a/datafusion/sql/src/expr/function.rs b/datafusion/sql/src/expr/function.rs
index cdf61183eb3d..1fa190c6c9ee 100644
--- a/datafusion/sql/src/expr/function.rs
+++ b/datafusion/sql/src/expr/function.rs
@@ -349,6 +349,12 @@ impl<S: ContextProvider> SqlToRel<'_, S> {
         } else {
             // User defined aggregate functions (UDAF) have precedence in case it has the same name as a scalar built-in function
             if let Some(fm) = self.context_provider.get_aggregate_meta(&name) {
+                // Reject RESPECT NULLS and IGNORE NULLS for aggregate functions
+                // See https://github.com/apache/datafusion/issues/15006
+                if null_treatment.is_some() {
+                    return plan_err!("RESPECT NULLS and IGNORE NULLS are not supported for aggregate functions");
+                }
+
                 let order_by = self.order_by_to_sort_expr(
                     order_by,
                     schema,
@@ -369,7 +375,7 @@ impl<S: ContextProvider> SqlToRel<'_, S> {
                     distinct,
                     filter,
                     order_by,
-                    null_treatment,
+                    null_treatment: None, // See https://github.com/apache/datafusion/issues/15006
                 };
                 for planner in self.context_provider.get_expr_planners().iter() {
                     match planner.plan_aggregate(aggregate_expr)? {
diff --git a/datafusion/sqllogictest/test_files/aggregate.slt b/datafusion/sqllogictest/test_files/aggregate.slt
index bc43f6bc8e61..2450c88b1f8d 100644
--- a/datafusion/sqllogictest/test_files/aggregate.slt
+++ b/datafusion/sqllogictest/test_files/aggregate.slt
@@ -5863,15 +5863,11 @@ SELECT FIRST_VALUE(column1) FROM t;
 ----
 NULL
 
-query I
+query error DataFusion error: Error during planning: RESPECT NULLS and IGNORE NULLS are not supported for aggregate functions
 SELECT FIRST_VALUE(column1) RESPECT NULLS FROM t;
-----
-NULL
 
-query I
+query error DataFusion error: Error during planning: RESPECT NULLS and IGNORE NULLS are not supported for aggregate functions
 SELECT FIRST_VALUE(column1) IGNORE NULLS FROM t;
-----
-3
 
 statement ok
 DROP TABLE t;
@@ -5893,15 +5889,11 @@ SELECT FIRST_VALUE(column1 ORDER BY column2) FROM t;
 ----
 NULL
 
-query I
+query error DataFusion error: Error during planning: RESPECT NULLS and IGNORE NULLS are not supported for aggregate functions
 SELECT FIRST_VALUE(column1 ORDER BY column2) RESPECT NULLS FROM t;
-----
-NULL
 
-query I
+query error DataFusion error: Error during planning: RESPECT NULLS and IGNORE NULLS are not supported for aggregate functions
 SELECT FIRST_VALUE(column1 ORDER BY column2) IGNORE NULLS FROM t;
-----
-4
 
 statement ok
 DROP TABLE t;
@@ -5915,15 +5907,11 @@ SELECT LAST_VALUE(column1) FROM t;
 ----
 NULL
 
-query I
+query error DataFusion error: Error during planning: RESPECT NULLS and IGNORE NULLS are not supported for aggregate functions
 SELECT LAST_VALUE(column1) RESPECT NULLS FROM t;
-----
-NULL
 
-query I
+query error DataFusion error: Error during planning: RESPECT NULLS and IGNORE NULLS are not supported for aggregate functions
 SELECT LAST_VALUE(column1) IGNORE NULLS FROM t;
-----
-4
 
 statement ok
 DROP TABLE t;
@@ -5945,15 +5933,11 @@ SELECT LAST_VALUE(column1 ORDER BY column2 DESC) FROM t;
 ----
 NULL
 
-query I
+query error DataFusion error: Error during planning: RESPECT NULLS and IGNORE NULLS are not supported for aggregate functions
 SELECT LAST_VALUE(column1 ORDER BY column2 DESC) RESPECT NULLS FROM t;
-----
-NULL
 
-query I
+query error DataFusion error: Error during planning: RESPECT NULLS and IGNORE NULLS are not supported for aggregate functions
 SELECT LAST_VALUE(column1 ORDER BY column2 DESC) IGNORE NULLS FROM t;
-----
-3
 
 statement ok
 DROP TABLE t;