diff --git a/src/mito2/src/compaction.rs b/src/mito2/src/compaction.rs
index 7d4302cb74..f284c732ff 100644
--- a/src/mito2/src/compaction.rs
+++ b/src/mito2/src/compaction.rs
@@ -1005,10 +1005,11 @@ impl CompactionSstReaderBuilder<'_> {
     /// Build a [FlatSource] that yields Arrow `RecordBatch`s from reading all the input SST files,
     /// for compaction. The schema of the [FlatSource] is unified.
     async fn build_flat_sst_reader(self) -> Result<FlatSource> {
-        let scan_input = self.build_scan_input().await?.with_compaction(true);
+        let compaction = true;
+        let scan_input = self.build_scan_input().await?.with_compaction(compaction);
         // Compaction reads/writes flat SST batches (with internal columns), so this must use
         // the flat input schema instead of the logical output schema.
-        let schema = scan_input.mapper.input_arrow_schema(scan_input.compaction);
+        let schema = scan_input.mapper.input_arrow_schema(compaction);
 
         let stream = SeqScan::new(scan_input)
             .build_flat_reader_for_compaction()