diff --git a/rts/CMakeLists.txt b/rts/CMakeLists.txt
index 001ea7cb6b..5571f4dd17 100644
--- a/rts/CMakeLists.txt
+++ b/rts/CMakeLists.txt
@@ -142,7 +142,12 @@ make_global_var(engineSources
 		${sources_engine_ExternalAI}
 	)
 include_directories(${CMAKE_CURRENT_SOURCE_DIR}/lib/assimp/include) #FIXME: hack for rts/Rendering/Models/IModelParser.cpp
-include_directories(${CMAKE_CURRENT_SOURCE_DIR}/lib/simdjson/include)
+# On macOS, locating DevIL via Homebrew pulls /opt/homebrew/include onto the
+# global include path, where a transitively-installed Homebrew simdjson.h can
+# shadow our vendored, version-matched copy and break the build (newer simdjson
+# trips an AppleClang macro collision). Prepend so <simdjson.h> always resolves
+# to the in-tree version on every platform.
+include_directories(BEFORE ${CMAKE_CURRENT_SOURCE_DIR}/lib/simdjson/include)
 include_directories(${CMAKE_CURRENT_SOURCE_DIR}/lib/fastgltf/include)
 
 ### Add headers for generated project files (e.g. Code::Blocks)