diff --git a/CMakeLists.txt b/CMakeLists.txt
index b3211f82d..f50c5802e 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -319,7 +319,7 @@ if(HAVE_LOCALTIME_R)
 	list(APPEND FUNCTION_DEFINES HAVE_LOCALTIME_R)
 endif()
 
-if(HAVE_NEWLOCALE AND HAVE_FREELOCALE AND HAVE_USELOCALE OR APPLE OR 3DS)
+if(HAVE_NEWLOCALE AND HAVE_FREELOCALE AND HAVE_USELOCALE OR APPLE OR DEFINED 3DS)
 	list(APPEND FUNCTION_DEFINES HAVE_LOCALE)
 	if (HAVE_STRTOF_L)
 		list(APPEND FUNCTION_DEFINES HAVE_STRTOF_L)
@@ -639,15 +639,15 @@ source_group("Extra features" FILES ${FEATURE_SRC})
 source_group("Third-party code" FILES ${THIRD_PARTY_SRC})
 
 # Platform binaries
-if(3DS)
+if(DEFINED 3DS)
 	add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/src/platform/3ds ${CMAKE_CURRENT_BINARY_DIR}/3ds)
 endif()
 
-if(WII)
+if(DEFINED WII)
 	add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/src/platform/wii ${CMAKE_CURRENT_BINARY_DIR}/wii)
 endif()
 
-if(PSP2)
+if(DEFINED PSP2)
 	add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/src/platform/psp2 ${CMAKE_CURRENT_BINARY_DIR}/psp2)
 endif()