diff --git a/llvm/include/llvm/Support/Allocator.h b/llvm/include/llvm/Support/Allocator.h
--- a/llvm/include/llvm/Support/Allocator.h
+++ b/llvm/include/llvm/Support/Allocator.h
@@ -79,6 +79,11 @@
   BumpPtrAllocatorImpl(T &&Allocator)
       : AllocatorT(std::forward<T &&>(Allocator)) {}
 
+  // BumpPtrAllocator shouldn't be copyable. Explicitly delete this
+  // specialization of the perfect-forwarding constructor above.
+  template <typename T>
+  BumpPtrAllocatorImpl(BumpPtrAllocatorImpl<T> &) = delete;
+
   // Manually implement a move constructor as we must clear the old allocator's
   // slabs as a matter of correctness.
   BumpPtrAllocatorImpl(BumpPtrAllocatorImpl &&Old)