diff --git a/build_settings.cmake b/build_settings.cmake
index a6e2490f1171..0976e73442e5 100644
--- a/build_settings.cmake
+++ b/build_settings.cmake
@@ -85,6 +85,9 @@ else()
 endif()
 if(CMAKE_HOST_SYSTEM_NAME STREQUAL "Darwin")
   set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -DGOOGLE_PROTOBUF_NO_RDTSC")
+  if(CMAKE_CXX_COMPILER_ID STREQUAL "Clang" AND CMAKE_CXX_COMPILER_VERSION VERSION_GREATER_EQUAL 15.0)
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -DBOOST_NO_CXX98_FUNCTION_BASE")
+  endif()
 endif()
 
 # Linker flags
diff --git a/default_build_settings.cmake b/default_build_settings.cmake
index fe17192b6b88..08f5e7d14daf 100644
--- a/default_build_settings.cmake
+++ b/default_build_settings.cmake
@@ -40,7 +40,7 @@ endfunction()
 
 function(setup_vespa_default_build_settings_darwin)
   message("-- Setting up default build settings for darwin")
-  set(DEFAULT_VESPA_LLVM_VERSION "14" PARENT_SCOPE)
+  set(DEFAULT_VESPA_LLVM_VERSION "15" PARENT_SCOPE)
   set(DEFAULT_CMAKE_PREFIX_PATH "${VESPA_DEPS}" "/usr/local/opt/bison" "/usr/local/opt/flex" "/usr/local/opt/openssl@1.1" "/usr/local/opt/openblas" "/usr/local/opt/icu4c" PARENT_SCOPE)
   set(DEFAULT_EXTRA_LINK_DIRECTORY "${VESPA_DEPS}/lib" "/usr/local/opt/bison/lib" "/usr/local/opt/flex/lib" "/usr/local/opt/icu4c/lib" "/usr/local/opt/openssl@1.1/lib" "/usr/local/opt/openblas/lib")
   list(APPEND DEFAULT_EXTRA_LINK_DIRECTORY "/usr/local/lib")