diff --git a/packages/jaeger-ui/src/components/TracePage/TraceTimelineViewer/SpanTreeOffset.js b/packages/jaeger-ui/src/components/TracePage/TraceTimelineViewer/SpanTreeOffset.js
index d54068fec8..361c96df29 100644
--- a/packages/jaeger-ui/src/components/TracePage/TraceTimelineViewer/SpanTreeOffset.js
+++ b/packages/jaeger-ui/src/components/TracePage/TraceTimelineViewer/SpanTreeOffset.js
@@ -56,7 +56,6 @@ export class UnconnectedSpanTreeOffset extends React.PureComponent<SpanTreeOffse
     super(props);
 
     this.ancestorIds = spanAncestorIds(props.span);
-
     // Some traces have multiple root-level spans, this connects them all under one guideline and adds the
     // necessary padding for the collapse icon on root-level spans.
     this.ancestorIds.push('root');
diff --git a/packages/jaeger-ui/src/components/TracePage/TraceTimelineViewer/SpanTreeOffset.test.js b/packages/jaeger-ui/src/components/TracePage/TraceTimelineViewer/SpanTreeOffset.test.js
index 7a764e28bd..572b3847cc 100644
--- a/packages/jaeger-ui/src/components/TracePage/TraceTimelineViewer/SpanTreeOffset.test.js
+++ b/packages/jaeger-ui/src/components/TracePage/TraceTimelineViewer/SpanTreeOffset.test.js
@@ -31,7 +31,8 @@ describe('SpanTreeOffset', () => {
   let wrapper;
 
   beforeEach(() => {
-    spanAncestorIdsSpy.mockReturnValue([parentSpanID, rootSpanID]);
+    // Mock implementation instead of Mock return value so that each call returns a new array (like normal)
+    spanAncestorIdsSpy.mockImplementation(() => [parentSpanID, rootSpanID]);
     props = {
       addHoverIndentGuideId: jest.fn(),
       hoverIndentGuideIds: new Set(),