diff --git a/crates/sui-indexer/migrations/pg/2024-09-12-213234_watermarks/up.sql b/crates/sui-indexer/migrations/pg/2024-09-12-213234_watermarks/up.sql
index 57dd6e130954d..e8499c692120c 100644
--- a/crates/sui-indexer/migrations/pg/2024-09-12-213234_watermarks/up.sql
+++ b/crates/sui-indexer/migrations/pg/2024-09-12-213234_watermarks/up.sql
@@ -22,5 +22,8 @@ CREATE TABLE watermarks
     -- be dropped. The pruner uses this column to determine whether to prune or wait long enough
     -- that all in-flight reads complete or timeout before it acts on an updated watermark.
     timestamp_ms                BIGINT        NOT NULL,
+    -- Column used by the pruner to track its true progress. Data at and below this watermark can
+    -- be immediately pruned.
+    pruner_lo                   BIGINT,
     PRIMARY KEY (entity)
 );
diff --git a/crates/sui-indexer/src/models/watermarks.rs b/crates/sui-indexer/src/models/watermarks.rs
index e3e815a16a3d4..a04d99a1404c2 100644
--- a/crates/sui-indexer/src/models/watermarks.rs
+++ b/crates/sui-indexer/src/models/watermarks.rs
@@ -36,6 +36,9 @@ pub struct StoredWatermark {
     /// be dropped. The pruner uses this column to determine whether to prune or wait long enough
     /// that all in-flight reads complete or timeout before it acts on an updated watermark.
     pub timestamp_ms: i64,
+    /// Column used by the pruner to track its true progress. Data at and below this watermark can
+    /// be immediately pruned.
+    pub pruner_lo: Option<i64>,
 }
 
 impl StoredWatermark {
diff --git a/crates/sui-indexer/src/schema.rs b/crates/sui-indexer/src/schema.rs
index 7f5260c53eb5f..a2c418db8e042 100644
--- a/crates/sui-indexer/src/schema.rs
+++ b/crates/sui-indexer/src/schema.rs
@@ -378,6 +378,7 @@ diesel::table! {
         tx_hi_inclusive -> Int8,
         reader_lo -> Int8,
         timestamp_ms -> Int8,
+        pruner_lo -> Nullable<Int8>,
     }
 }