diff --git a/llvm/include/llvm/Support/MemAlloc.h b/llvm/include/llvm/Support/MemAlloc.h
index f3f378b7697a1..19284f6e72087 100644
--- a/llvm/include/llvm/Support/MemAlloc.h
+++ b/llvm/include/llvm/Support/MemAlloc.h
@@ -71,7 +71,7 @@ LLVM_ATTRIBUTE_RETURNS_NONNULL inline void *safe_realloc(void *Ptr, size_t Sz) {
 /// like posix_memalign due to portability. It is mostly intended to allow
 /// compatibility with platforms that, after aligned allocation was added, use
 /// reduced default alignment.
-LLVM_ATTRIBUTE_RETURNS_NONNULL LLVM_ATTRIBUTE_RETURNS_NOALIAS void *
+LLVM_ABI LLVM_ATTRIBUTE_RETURNS_NONNULL LLVM_ATTRIBUTE_RETURNS_NOALIAS void *
 allocate_buffer(size_t Size, size_t Alignment);
 
 /// Deallocate a buffer of memory with the given size and alignment.
@@ -81,6 +81,7 @@ allocate_buffer(size_t Size, size_t Alignment);
 ///
 /// The pointer must have been allocated with the corresponding new operator,
 /// most likely using the above helper.
+LLVM_ABI
 void deallocate_buffer(void *Ptr, size_t Size, size_t Alignment);
 
 } // namespace llvm