diff --git a/RecoLocalTracker/SiPixelRecHits/plugins/SiPixelRecHitFromCUDA.cc b/RecoLocalTracker/SiPixelRecHits/plugins/SiPixelRecHitFromCUDA.cc
index 790b0da51ecfb..0bad87176ef7a 100644
--- a/RecoLocalTracker/SiPixelRecHits/plugins/SiPixelRecHitFromCUDA.cc
+++ b/RecoLocalTracker/SiPixelRecHits/plugins/SiPixelRecHitFromCUDA.cc
@@ -85,7 +85,8 @@ void SiPixelRecHitFromCUDA::acquire(edm::Event const& iEvent,
 void SiPixelRecHitFromCUDA::produce(edm::Event& iEvent, edm::EventSetup const& es) {
   // allocate a buffer for the indices of the clusters
   auto hmsp = std::make_unique<uint32_t[]>(gpuClustering::maxNumModules + 1);
-  std::copy(hitsModuleStart_.get(), hitsModuleStart_.get() + gpuClustering::maxNumModules + 1, hmsp.get());
+  if (hitsModuleStart_)
+    std::copy(hitsModuleStart_.get(), hitsModuleStart_.get() + gpuClustering::maxNumModules + 1, hmsp.get());
   // wrap the buffer in a HostProduct, and move it to the Event, without reallocating the buffer or affecting hitsModuleStart
   iEvent.emplace(hostPutToken_, std::move(hmsp));