diff --git a/CMakeLists.txt b/CMakeLists.txt
index 9d81a67f26..b4fb7b17a3 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -360,9 +360,6 @@ endif()
 # Required for building the FFmpeg headers
 add_definitions(-D__STDC_CONSTANT_MACROS)
 
-# Required for unity build
-add_definitions(-DMYGUI_DONT_REPLACE_NULLPTR)
-
 # TinyXML
 option(USE_SYSTEM_TINYXML "Use system TinyXML library instead of internal." OFF)
 if (USE_SYSTEM_TINYXML)