diff --git a/src/libbson/src/bson/bson-memory.c b/src/libbson/src/bson/bson-memory.c
index 8eb8f177575..1a9fca4fcef 100644
--- a/src/libbson/src/bson/bson-memory.c
+++ b/src/libbson/src/bson/bson-memory.c
@@ -33,7 +33,7 @@ BSON_STATIC_ASSERT2 (bson_mem_vtable_t,
 // For compatibility with C standards prior to C11.
 static void *
 _aligned_alloc_impl (size_t alignment, size_t num_bytes)
-#if __STDC_VERSION__ >= 201112L
+#if __STDC_VERSION__ >= 201112L && !defined(_WIN32)
 {
    return aligned_alloc (alignment, num_bytes);
 }