diff --git a/includes/utilities.php b/includes/utilities.php
index 5978072..c2cd183 100644
--- a/includes/utilities.php
+++ b/includes/utilities.php
@@ -147,11 +147,14 @@ function processLogEntries($logEntries, $user, $insertStmt) {
             continue;
         }
 
+        $runningBalance = isset($entry['data']['balance']) ? (int)$entry['data']['balance'] : null;
+
         $insertStmt->bindValue(':id', $id);
         $insertStmt->bindValue(':user', $user);
         $insertStmt->bindValue(':timestamp', $timestamp);
         $insertStmt->bindValue(':description', $description);
         $insertStmt->bindValue(':amount', $amount);
+        $insertStmt->bindValue(':running_balance', $runningBalance);
         $insertStmt->execute();
     }
 }
@@ -250,8 +253,8 @@ function fetchAndStoreLogPage($pdo, $user, $url) {
     validateApiResponse($responseData);
 
     $insertStmt = $pdo->prepare(
-        'INSERT INTO vault (id, user, timestamp, description, amount) '
-        . 'VALUES (:id, :user, :timestamp, :description, :amount) '
+        'INSERT INTO vault (id, user, timestamp, description, amount, running_balance) '
+        . 'VALUES (:id, :user, :timestamp, :description, :amount, :running_balance) '
         . 'ON CONFLICT(id) DO NOTHING'
     );
 
diff --git a/tests/process_log_entries_test.php b/tests/process_log_entries_test.php
index 39c8c6c..e78455a 100644
--- a/tests/process_log_entries_test.php
+++ b/tests/process_log_entries_test.php
@@ -69,17 +69,18 @@ $pdo = new PDO('sqlite::memory:');
 $pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
 $pdo->exec(
     'CREATE TABLE vault (
-        id          TEXT PRIMARY KEY,
-        user        TEXT NOT NULL,
-        timestamp   INTEGER NOT NULL,
-        description TEXT NOT NULL,
-        amount      REAL NOT NULL
+        id              TEXT PRIMARY KEY,
+        user            TEXT NOT NULL,
+        timestamp       INTEGER NOT NULL,
+        description     TEXT NOT NULL,
+        amount          REAL NOT NULL,
+        running_balance INTEGER
     )'
 );
 
 $insertStmt = $pdo->prepare(
-    'INSERT INTO vault (id, user, timestamp, description, amount) '
-    . 'VALUES (:id, :user, :timestamp, :description, :amount) '
+    'INSERT INTO vault (id, user, timestamp, description, amount, running_balance) '
+    . 'VALUES (:id, :user, :timestamp, :description, :amount, :running_balance) '
     . 'ON CONFLICT(id) DO NOTHING'
 );
 
@@ -100,7 +101,7 @@ $count = (int)$pdo->query('SELECT COUNT(*) FROM vault')->fetchColumn();
 assertSame(100, $count, 'row count');
 
 // Spot-check first entry (newest, withdraw) and last (oldest, deposit).
-$rows = $pdo->query('SELECT id, user, timestamp, description, amount FROM vault ORDER BY timestamp DESC')->fetchAll(PDO::FETCH_ASSOC);
+$rows = $pdo->query('SELECT id, user, timestamp, description, amount, running_balance FROM vault ORDER BY timestamp DESC')->fetchAll(PDO::FETCH_ASSOC);
 
 $first = $rows[0];
 assertSame('c1pEDQ7jl3kuBHV4NqDI', $first['id'], 'first.id');
@@ -120,4 +121,10 @@ processLogEntries($fixture['log'], 'zarathos', $insertStmt);
 $count2 = (int)$pdo->query('SELECT COUNT(*) FROM vault')->fetchColumn();
 assertSame(100, $count2, 'row count after re-run');
 
+// round-trip the running_balance column from $entry['data']['balance']
+$firstRunning = (int)$first['running_balance'];
+$lastRunning  = (int)$last['running_balance'];
+assertSame(69235831, $firstRunning, 'first.running_balance');
+assertSame(509622821, $lastRunning, 'last.running_balance');
+
 echo "OK: processLogEntries v2 golden-file test passed (100 entries).\n";