diff --git a/src/mol-state/state.ts b/src/mol-state/state.ts
index cbb5e4ae1368aed15307e7f5d49f03705ff5ca77..c11fc78d078dbe0c5f345a11232224bfff059e4e 100644
--- a/src/mol-state/state.ts
+++ b/src/mol-state/state.ts
@@ -162,7 +162,7 @@ class State {
                 return cell && cell.obj;
             }
         } finally {
-            this.spine.setCurrent();
+            this.spine.current = undefined;
 
             if (updated) this.events.changed.next();
             this.events.isUpdating.next(false);
@@ -607,7 +607,7 @@ async function updateNode(ctx: UpdateContext, currentRef: Ref): Promise<UpdateNo
         throw new Error(`No suitable parent found for '${currentRef}'`);
     }
 
-    ctx.spine.setCurrent(current);
+    ctx.spine.current = current;
 
     const parent = parentCell.obj!;
     current.sourceRef = parentCell.transform.ref;
diff --git a/src/mol-state/tree/spine.ts b/src/mol-state/tree/spine.ts
index e623ec41a19e4638d32ca69087a1fc199f9274f2..9adc01e7c86a5d299ac998b112258af828e94785 100644
--- a/src/mol-state/tree/spine.ts
+++ b/src/mol-state/tree/spine.ts
@@ -18,14 +18,14 @@ interface StateTreeSpine {
 
 namespace StateTreeSpine {
     export class Impl implements StateTreeSpine {
-        private current: StateObjectCell | undefined = void 0;
-        setCurrent(cell?: StateObjectCell) {
-            this.current = cell;
-        }
+        private _current: StateObjectCell | undefined = void 0;
+
+        get current() { return this._current; }
+        set current(cell: StateObjectCell | undefined) { this._current = cell; }
 
         getAncestorOfType<T extends StateObject.Ctor>(t: T): StateObject.From<T> | undefined {
-            if (!this.current) return void 0;
-            let cell = this.current;
+            if (!this._current) return void 0;
+            let cell = this._current;
             while (true) {
                 cell = this.cells.get(cell.transform.parent)!;
                 if (!cell.obj) return void 0;
@@ -35,8 +35,8 @@ namespace StateTreeSpine {
         }
 
         getRootOfType<T extends StateObject.Ctor>(t: T): StateObject.From<T> | undefined {
-            if (!this.current) return void 0;
-            let cell = this.current;
+            if (!this._current) return void 0;
+            let cell = this._current;
             let ret: StateObjectCell | undefined = void 0;
             while (true) {
                 cell = this.cells.get(cell.transform.parent)!;