diff --git a/render/benchmark_test.go b/render/benchmark_test.go
index eb3516e44..3c53148d5 100644
--- a/render/benchmark_test.go
+++ b/render/benchmark_test.go
@@ -61,6 +61,7 @@ func benchmarkRender(b *testing.B, r render.Renderer) {
 	b.ResetTimer()
 
 	for i := 0; i < b.N; i++ {
+		render.ResetCache()
 		benchmarkRenderResult = r.Render(report)
 		if len(benchmarkRenderResult) == 0 {
 			b.Errorf("Rendered topology contained no nodes")
@@ -78,6 +79,7 @@ func benchmarkStats(b *testing.B, r render.Renderer) {
 
 	for i := 0; i < b.N; i++ {
 		// No way to tell if this was successful :(
+		render.ResetCache()
 		benchmarkStatsResult = r.Stats(report)
 	}
 }
diff --git a/render/render.go b/render/render.go
index a8d9a6f6e..6e6ad4731 100644
--- a/render/render.go
+++ b/render/render.go
@@ -30,6 +30,10 @@ func memoisedRender(r Renderer, rpt report.Report) RenderableNodes {
 	return output
 }
 
+func ResetCache() {
+	renderCache.Purge()
+}
+
 // Renderer is something that can render a report to a set of RenderableNodes.
 type Renderer interface {
 	Render(report.Report) RenderableNodes