diff --git a/tsdb/agent/db.go b/tsdb/agent/db.go
index d47095a23..2ed51e4b8 100644
--- a/tsdb/agent/db.go
+++ b/tsdb/agent/db.go
@@ -985,11 +985,25 @@ func (a *appender) UpdateMetadata(storage.SeriesRef, labels.Labels, metadata.Met
 
 // Commit submits the collected samples and purges the batch.
 func (a *appender) Commit() error {
+	if err := a.log(); err != nil {
+		return err
+	}
+
+	a.clearData()
+	a.appenderPool.Put(a)
+	return nil
+}
+
+// log logs all pending data to the WAL.
+func (a *appender) log() error {
 	a.mtx.RLock()
 	defer a.mtx.RUnlock()
 
 	var encoder record.Encoder
 	buf := a.bufPool.Get().([]byte)
+	defer func() {
+		a.bufPool.Put(buf) //nolint:staticcheck
+	}()
 
 	if len(a.pendingSeries) > 0 {
 		buf = encoder.Series(a.pendingSeries, buf)
@@ -1051,12 +1065,11 @@ func (a *appender) Commit() error {
 		}
 	}
 
-	//nolint:staticcheck
-	a.bufPool.Put(buf)
-	return a.Rollback()
+	return nil
 }
 
-func (a *appender) Rollback() error {
+// clearData clears all pending data.
+func (a *appender) clearData() {
 	a.pendingSeries = a.pendingSeries[:0]
 	a.pendingSamples = a.pendingSamples[:0]
 	a.pendingHistograms = a.pendingHistograms[:0]
@@ -1065,6 +1078,39 @@ func (a *appender) Rollback() error {
 	a.sampleSeries = a.sampleSeries[:0]
 	a.histogramSeries = a.histogramSeries[:0]
 	a.floatHistogramSeries = a.floatHistogramSeries[:0]
+}
+
+func (a *appender) Rollback() error {
+	// Series are created in-memory regardless of rollback. This means we must
+	// log them to the WAL, otherwise subsequent commits may reference a series
+	// which was never written to the WAL.
+	if err := a.logSeries(); err != nil {
+		return err
+	}
+
+	a.clearData()
 	a.appenderPool.Put(a)
 	return nil
 }
+
+// logSeries logs only pending series records to the WAL.
+func (a *appender) logSeries() error {
+	a.mtx.RLock()
+	defer a.mtx.RUnlock()
+
+	if len(a.pendingSeries) > 0 {
+		buf := a.bufPool.Get().([]byte)
+		defer func() {
+			a.bufPool.Put(buf) //nolint:staticcheck
+		}()
+
+		var encoder record.Encoder
+		buf = encoder.Series(a.pendingSeries, buf)
+		if err := a.wal.Log(buf); err != nil {
+			return err
+		}
+		buf = buf[:0]
+	}
+
+	return nil
+}
diff --git a/tsdb/agent/db_test.go b/tsdb/agent/db_test.go
index e284e1b77..5c71d548f 100644
--- a/tsdb/agent/db_test.go
+++ b/tsdb/agent/db_test.go
@@ -333,8 +333,8 @@ func TestRollback(t *testing.T) {
 		}
 	}
 
-	// Check that the rollback ensured nothing got stored.
-	require.Equal(t, 0, walSeriesCount, "series should not have been written to WAL")
+	// Check that only series get stored after calling Rollback.
+	require.Equal(t, numSeries*3, walSeriesCount, "series should have been written to WAL")
 	require.Equal(t, 0, walSamplesCount, "samples should not have been written to WAL")
 	require.Equal(t, 0, walExemplarsCount, "exemplars should not have been written to WAL")
 	require.Equal(t, 0, walHistogramCount, "histograms should not have been written to WAL")