diff --git a/intern/cycles/kernel/osl/CMakeLists.txt b/intern/cycles/kernel/osl/CMakeLists.txt
index fc0c845fd4f..d7ab778181e 100644
--- a/intern/cycles/kernel/osl/CMakeLists.txt
+++ b/intern/cycles/kernel/osl/CMakeLists.txt
@@ -36,6 +36,15 @@ set(LIB
 # OSL and LLVM are built without RTTI
 set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${RTTI_DISABLE_FLAGS}")
 
+if(APPLE)
+  # Disable allocation warning on macOS prior to 10.14: the OSLRenderServices
+  # contains member which is 64 bytes aligned (cache inside of OIIO's
+  # unordered_map_concurrent). This is not something what the SDK supportsm, but
+  # since we take care of allocations ourselves is is OK to ignore the
+  # diagnostic message.
+  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -faligned-allocation")
+endif()
+
 include_directories(${INC})
 include_directories(SYSTEM ${INC_SYS})