diff --git a/CMakeLists.txt b/CMakeLists.txt
index e61256f03..2c24e7921 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -9,6 +9,9 @@ if (CMAKE_MAJOR_VERSION LESS 3)
     "MP: CMake version 3.0 or newer is required to install all targets")
 endif ()
 
+# Minimum MacOS target to enable C++17 std::filesystem
+set(CMAKE_OSX_DEPLOYMENT_TARGET 10.15)
+
 # Set the path to CMake modules.
 set(MP_CMAKE_MODULE_DIR ${CMAKE_CURRENT_SOURCE_DIR}/support/cmake)
 set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} ${MP_CMAKE_MODULE_DIR})
diff --git a/nl-writer2/CMakeLists.txt b/nl-writer2/CMakeLists.txt
index b9132960a..bd837bbd3 100644
--- a/nl-writer2/CMakeLists.txt
+++ b/nl-writer2/CMakeLists.txt
@@ -1,5 +1,10 @@
 cmake_minimum_required(VERSION 3.10)
 
+
+# Minimum MacOS target to enable C++17 std::filesystem
+set(CMAKE_OSX_DEPLOYMENT_TARGET 10.15)
+
+
 project(NLWriter2)
 
 
diff --git a/nl-writer2/src/nl-solver.cc b/nl-writer2/src/nl-solver.cc
index e188b349b..bacdcc0d8 100644
--- a/nl-writer2/src/nl-solver.cc
+++ b/nl-writer2/src/nl-solver.cc
@@ -30,6 +30,8 @@
 
 #if defined(_WIN32) || defined(_WIN64)
   #include <io.h>     // _mktemp[_s]
+#elif __APPLE__
+  #include <unistd.h> // mkdtemp
 #else
   #include <cstdlib>  // mkdtemp
 #endif
@@ -554,9 +556,6 @@ void NLSolver::InitAutoStub() {
   if (!std::filesystem::create_directory(pathstr_))
     Utils().myexit("Could not create temp dir '"
                    + pathstr_ + "'");
-#elif __APPLE__
-  if (!std::filesystem::create_directory(pathstr_))
-    Utils().myexit("Could not create temp dir '" + pathstr_ + "'");
 #else
   if (!mkdtemp((char*)pathstr_.c_str()))
     Utils().myexit("Could not create a temp dir\n"