diff --git a/datafusion/core/tests/fuzz_cases/aggregation_fuzzer/data_generator.rs b/datafusion/core/tests/fuzz_cases/aggregation_fuzzer/data_generator.rs
index a3a8271ba8d3..e4c0cb6fe77f 100644
--- a/datafusion/core/tests/fuzz_cases/aggregation_fuzzer/data_generator.rs
+++ b/datafusion/core/tests/fuzz_cases/aggregation_fuzzer/data_generator.rs
@@ -87,12 +87,7 @@ impl DatasetGeneratorConfig {
             .iter()
             .filter_map(|d| {
                 if d.column_type.is_numeric()
-                    && !matches!(
-                        d.column_type,
-                        DataType::Float32
-                            | DataType::Float64
-                            | DataType::Decimal128(_, _)
-                    )
+                    && !matches!(d.column_type, DataType::Float32 | DataType::Float64)
                 {
                     Some(d.name.as_str())
                 } else {
diff --git a/datafusion/physical-plan/src/aggregates/group_values/multi_group_by/primitive.rs b/datafusion/physical-plan/src/aggregates/group_values/multi_group_by/primitive.rs
index 4686a78f24b0..4ceeb634bad2 100644
--- a/datafusion/physical-plan/src/aggregates/group_values/multi_group_by/primitive.rs
+++ b/datafusion/physical-plan/src/aggregates/group_values/multi_group_by/primitive.rs
@@ -200,10 +200,10 @@ impl<T: ArrowPrimitiveType, const NULLABLE: bool> GroupColumn
 
         let first_n_nulls = if NULLABLE { self.nulls.take_n(n) } else { None };
 
-        Arc::new(PrimitiveArray::<T>::new(
-            ScalarBuffer::from(first_n),
-            first_n_nulls,
-        ))
+        Arc::new(
+            PrimitiveArray::<T>::new(ScalarBuffer::from(first_n), first_n_nulls)
+                .with_data_type(self.data_type.clone()),
+        )
     }
 }