diff --git a/openmp/libomptarget/src/device.cpp b/openmp/libomptarget/src/device.cpp
--- a/openmp/libomptarget/src/device.cpp
+++ b/openmp/libomptarget/src/device.cpp
@@ -305,7 +305,9 @@
     DataMapMtx.unlock();
     // If not a host pointer and no present modifier, we need to wait for the
     // event if it exists.
-    if (!IsHostPtr && !HasPresentModifier) {
+    // Note: Entry might be nullptr because of zero length array section.
+    if (Entry != HostDataToTargetListTy::iterator() && !IsHostPtr &&
+        !HasPresentModifier) {
       Entry->lock();
       void *Event = Entry->getEvent();
       if (Event) {