diff --git a/dstore/events.go b/dstore/events.go
index a00d839..b7b7912 100644
--- a/dstore/events.go
+++ b/dstore/events.go
@@ -47,16 +47,16 @@ func (m *Mem) EventsAdd(ctx context.Context, path string, data [][]byte) ([]*eve
 	return out, idx, nil
 }
 
-func (m *Mem) Increment(ctx context.Context, path string, name string, n int64) (int64, error) {
+func (m *Mem) Increment(ctx context.Context, path string, name string, n int64) (int64, int64, error) {
 	doc, err := m.Get(ctx, path)
 	if err != nil {
-		return 0, err
+		return 0, 0, err
 	}
 	val := int64(0)
 	if doc != nil {
 		v, ok := doc.Get(name)
 		if err != nil {
-			return 0, err
+			return 0, 0, err
 		}
 		if !ok {
 			val = int64(0)
@@ -67,9 +67,9 @@ func (m *Mem) Increment(ctx context.Context, path string, name string, n int64)
 
 	next := val + n
 	if err := m.Set(ctx, path, map[string]interface{}{name: next}, MergeAll()); err != nil {
-		return 0, err
+		return 0, 0, err
 	}
-	return next, nil
+	return next, next - n + 1, nil
 }
 
 // EventPositions returns positions for event logs at the specified paths.
diff --git a/dstore/events/events.go b/dstore/events/events.go
index 9d1f3ef..3029b66 100644
--- a/dstore/events/events.go
+++ b/dstore/events/events.go
@@ -42,7 +42,8 @@ type Events interface {
 	EventPositions(ctx context.Context, paths []string) (map[string]*Position, error)
 
 	// Increment document name at path n amount.
-	Increment(ctx context.Context, path string, name string, n int64) (int64, error)
+	// Returns the new value and the start of the index.
+	Increment(ctx context.Context, path string, name string, n int64) (int64, int64, error)
 }
 
 // Direction is ascending or descending.
diff --git a/dstore/events/events_test.go b/dstore/events/events_test.go
index f9724ed..a33d573 100644
--- a/dstore/events/events_test.go
+++ b/dstore/events/events_test.go
@@ -200,11 +200,13 @@ func TestIncrement(t *testing.T) {
 	clock := tsutil.NewTestClock()
 	eds.SetClock(clock)
 
-	n, err := eds.Increment(context.TODO(), "/test/doc1", "count", 1)
+	n, i, err := eds.Increment(context.TODO(), "/test/doc1", "count", 1)
 	require.NoError(t, err)
 	require.Equal(t, int64(1), n)
+	require.Equal(t, int64(1), i)
 
-	n, err = eds.Increment(context.TODO(), "/test/doc1", "count", 5)
+	n, i, err = eds.Increment(context.TODO(), "/test/doc1", "count", 5)
 	require.NoError(t, err)
 	require.Equal(t, int64(6), n)
+	require.Equal(t, int64(2), i)
 }