diff --git a/flang/runtime/derived.cpp b/flang/runtime/derived.cpp
--- a/flang/runtime/derived.cpp
+++ b/flang/runtime/derived.cpp
@@ -231,8 +231,9 @@
     if (comp.genre() == typeInfo::Component::Genre::Allocatable ||
         comp.genre() == typeInfo::Component::Genre::Automatic) {
       for (std::size_t j{0}; j < elements; ++j) {
-        descriptor.OffsetElement<Descriptor>(j * byteStride + comp.offset())
-            ->Deallocate();
+        Descriptor *d{reinterpret_cast<Descriptor *>(
+            descriptor.ZeroBasedIndexedElement<char>(j) + comp.offset())};
+        d->Deallocate();
       }
     }
   }