diff --git a/.circleci/config.yml b/.circleci/config.yml
index b9d46eea4..928a13534 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -39,7 +39,7 @@ executors:
 
   mac:
     macos:
-      xcode: 15.4.0
+      xcode: 16.0.0
     environment:
       CODENAME: mac
       OMP_NUM_THREADS: 4
diff --git a/libraries/Standard/src/primitive/primitive.birch b/libraries/Standard/src/primitive/primitive.birch
index 10ef2b40a..518f797ae 100644
--- a/libraries/Standard/src/primitive/primitive.birch
+++ b/libraries/Standard/src/primitive/primitive.birch
@@ -444,7 +444,7 @@ function is_sorted<Type>(x:Type[_]) -> Boolean {
 function sort<Type>(x:Type[_]) -> Type[_] {
   let y <- x;
   cpp{{
-  std::sort(y.begin(), y.end());
+  std::stable_sort(y.begin(), y.end());
   }}
   return y;
 }
diff --git a/numbirch/numbirch/array/ArrayIterator.hpp b/numbirch/numbirch/array/ArrayIterator.hpp
index 42b9fa827..34e9129e5 100644
--- a/numbirch/numbirch/array/ArrayIterator.hpp
+++ b/numbirch/numbirch/array/ArrayIterator.hpp
@@ -23,6 +23,10 @@ class ArrayIterator {
   using const_reference = const T&;
   using iterator_category = std::random_access_iterator_tag;
 
+  ArrayIterator() : buf(nullptr), shp(), pos(0) {
+    //
+  }
+
   explicit ArrayIterator(T* buf, const ArrayShape<D> shp,
       const difference_type pos) :
       buf(buf),