diff --git a/src/wx/CMakeLists.txt b/src/wx/CMakeLists.txt
index 83d76eda..fcc84b56 100644
--- a/src/wx/CMakeLists.txt
+++ b/src/wx/CMakeLists.txt
@@ -278,6 +278,7 @@ function(configure_wx_target target)
 
     # OpenAL.
     if(ENABLE_OPENAL)
+        _add_compile_definitions(VBAM_ENABLE_OPENAL)
         if(OPENAL_STATIC)
             _add_compile_definitions(AL_LIBTYPE_STATIC)
         endif()
diff --git a/third_party/sfml/src/SFML/System/CMakeLists.txt b/third_party/sfml/src/SFML/System/CMakeLists.txt
index bc928b9c..7c3a873b 100644
--- a/third_party/sfml/src/SFML/System/CMakeLists.txt
+++ b/third_party/sfml/src/SFML/System/CMakeLists.txt
@@ -73,8 +73,6 @@ endif()
 # define the sfml-system target
 add_library(sfml-system STATIC ${SRC} ${PLATFORM_SRC})
 
-include(SystemIncludeDirectories)
-
 target_include_directories(sfml-system SYSTEM BEFORE PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/../.. ${CMAKE_CURRENT_SOURCE_DIR}/../../../include)
 
 target_compile_definitions(sfml-system PRIVATE   SFML_STATIC)