diff --git a/src/mito2/src/compaction.rs b/src/mito2/src/compaction.rs
index a43fa8a0a6..a67110f8b8 100644
--- a/src/mito2/src/compaction.rs
+++ b/src/mito2/src/compaction.rs
@@ -60,7 +60,7 @@ use crate::error::{
 use crate::metrics::{COMPACTION_STAGE_ELAPSED, INFLIGHT_COMPACTION_COUNT};
 use crate::read::BoxedRecordBatchStream;
 use crate::read::projection::ProjectionMapper;
-use crate::read::scan_region::{PredicateGroup, ScanInput};
+use crate::read::scan_region::{PredicateGroup, ScanInput, concretize_json2_types};
 use crate::read::seq_scan::SeqScan;
 use crate::region::options::{MergeMode, RegionOptions};
 use crate::region::version::VersionControlRef;
@@ -840,14 +840,14 @@ struct CompactionSstReaderBuilder<'a> {
 impl CompactionSstReaderBuilder<'_> {
     /// Builds [BoxedRecordBatchStream] that reads all SST files and yields batches in flat format for compaction.
     async fn build_flat_sst_reader(self) -> Result<BoxedRecordBatchStream> {
-        let scan_input = self.build_scan_input()?.with_compaction(true);
+        let scan_input = self.build_scan_input().await?.with_compaction(true);
 
         SeqScan::new(scan_input)
             .build_flat_reader_for_compaction()
             .await
     }
 
-    fn build_scan_input(self) -> Result<ScanInput> {
+    async fn build_scan_input(self) -> Result<ScanInput> {
         let mapper = ProjectionMapper::all(&self.metadata, true)?;
         let mut scan_input = ScanInput::new(self.sst_layer, mapper)
             .with_files(self.inputs.to_vec())
@@ -867,7 +867,7 @@ impl CompactionSstReaderBuilder<'_> {
                 scan_input.with_predicate(time_range_to_predicate(time_range, &self.metadata)?);
         }
 
-        Ok(scan_input)
+        concretize_json2_types(scan_input).await
     }
 }
 
diff --git a/src/mito2/src/read/scan_region.rs b/src/mito2/src/read/scan_region.rs
index 8cdc1cb12a..fce18eaee9 100644
--- a/src/mito2/src/read/scan_region.rs
+++ b/src/mito2/src/read/scan_region.rs
@@ -806,7 +806,7 @@ impl ScanRegion {
     }
 }
 
-async fn concretize_json2_types(input: ScanInput) -> Result<ScanInput> {
+pub(crate) async fn concretize_json2_types(input: ScanInput) -> Result<ScanInput> {
     let Some(output_schema) = input.mapper.as_flat().map(|x| x.output_schema()) else {
         return Ok(input);
     };