diff --git a/CMakeLists.txt b/CMakeLists.txt
index ccf5475d..fc69437d 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -491,8 +491,13 @@ add_definitions(-D__STDC_FORMAT_MACROS)
 
 # For C++, default to nonstd::optional and nonstd::variant for now due to mac
 # build issues.
-add_definitions(-Doptional_CONFIG_SELECT_OPTIONAL=optional_OPTIONAL_NONSTD)
-add_definitions(-Dvariant_CONFIG_SELECT_VARIANT=variant_VARIANT_NONSTD)
+if(APPLE)
+    add_definitions(-Doptional_CONFIG_SELECT_OPTIONAL=optional_OPTIONAL_NONSTD)
+    add_definitions(-Dvariant_CONFIG_SELECT_VARIANT=variant_VARIANT_NONSTD)
+else()
+    add_definitions(-Doptional_CONFIG_SELECT_OPTIONAL=optional_OPTIONAL_STD)
+    add_definitions(-Dvariant_CONFIG_SELECT_VARIANT=variant_VARIANT_STD)
+endif()
 
 if(ENABLE_LINK)
     # IPC linking code needs sem_timedwait which can be either in librt or pthreads