diff --git a/CMakeLists.txt b/CMakeLists.txt
index 75068d852..d484956fd 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -74,6 +74,7 @@ find_package(PkgConfig)
 list(APPEND CMAKE_MODULE_PATH "${SDL2_SOURCE_DIR}/cmake")
 include(${SDL2_SOURCE_DIR}/cmake/macros.cmake)
 include(${SDL2_SOURCE_DIR}/cmake/sdlchecks.cmake)
+include(${SDL2_SOURCE_DIR}/cmake/sdlplatform.cmake)
 include(${SDL2_SOURCE_DIR}/cmake/CheckCPUArchitecture.cmake)
 
 # Enable large file support on 32-bit glibc, so that we can access files
@@ -156,56 +157,7 @@ if(NOT LIBTYPE)
 endif()
 
 # Get the platform
-if(WIN32)
-  if(NOT WINDOWS)
-    set(WINDOWS TRUE)
-  endif()
-elseif(UNIX AND NOT APPLE)
-  if(CMAKE_SYSTEM_NAME MATCHES ".*Linux")
-    set(LINUX TRUE)
-  elseif(CMAKE_SYSTEM_NAME MATCHES "kFreeBSD.*")
-    set(FREEBSD TRUE)
-  elseif(CMAKE_SYSTEM_NAME MATCHES "kNetBSD.*|NetBSD.*")
-    set(NETBSD TRUE)
-  elseif(CMAKE_SYSTEM_NAME MATCHES "kOpenBSD.*|OpenBSD.*")
-    set(OPENBSD TRUE)
-  elseif(CMAKE_SYSTEM_NAME MATCHES ".*GNU.*")
-    set(GNU TRUE)
-  elseif(CMAKE_SYSTEM_NAME MATCHES ".*BSDI.*")
-    set(BSDI TRUE)
-  elseif(CMAKE_SYSTEM_NAME MATCHES "DragonFly.*|FreeBSD")
-    set(FREEBSD TRUE)
-  elseif(CMAKE_SYSTEM_NAME MATCHES "SYSV5.*")
-    set(SYSV5 TRUE)
-  elseif(CMAKE_SYSTEM_NAME MATCHES "Solaris.*|SunOS.*")
-    set(SOLARIS TRUE)
-  elseif(CMAKE_SYSTEM_NAME MATCHES "HP-UX.*")
-    set(HPUX TRUE)
-  elseif(CMAKE_SYSTEM_NAME MATCHES "AIX.*")
-    set(AIX TRUE)
-  elseif(CMAKE_SYSTEM_NAME MATCHES "Minix.*")
-    set(MINIX TRUE)
-  endif()
-elseif(APPLE)
-  if(CMAKE_SYSTEM_NAME MATCHES ".*Darwin.*")
-    set(DARWIN TRUE)
-  elseif(CMAKE_SYSTEM_NAME MATCHES ".*MacOS.*")
-    set(MACOSX TRUE)
-  elseif(CMAKE_SYSTEM_NAME MATCHES ".*tvOS.*")
-    set(TVOS TRUE)
-  elseif(CMAKE_SYSTEM_NAME MATCHES ".*iOS.*")
-    # !!! FIXME: remove the version check when we start requiring >= 3.14.0
-    if(CMAKE_VERSION VERSION_LESS 3.14)
-      set(IOS TRUE)
-    endif()
-  endif()
-elseif(CMAKE_SYSTEM_NAME MATCHES "BeOS.*")
-  message_error("BeOS support has been removed as of SDL 2.0.2.")
-elseif(CMAKE_SYSTEM_NAME MATCHES "Haiku.*")
-  set(HAIKU TRUE)
-elseif(NINTENDO_3DS)
-  set(N3DS TRUE)
-endif()
+SDL_DetectCMakePlatform()
 
 # Don't mistake osx for unix
 if(UNIX AND NOT ANDROID AND NOT APPLE AND NOT RISCOS)
diff --git a/cmake/sdlplatform.cmake b/cmake/sdlplatform.cmake
new file mode 100644
index 000000000..f55ad313b
--- /dev/null
+++ b/cmake/sdlplatform.cmake
@@ -0,0 +1,55 @@
+macro(SDL_DetectCMakePlatform)
+  set(SDL_CMAKE_PLATFORM )
+  # Get the platform
+  if(WIN32)
+    set(SDL_CMAKE_PLATFORM WINDOWS)
+  elseif(UNIX AND NOT APPLE)
+    if(CMAKE_SYSTEM_NAME MATCHES ".*Linux")
+      set(SDL_CMAKE_PLATFORM LINUX)
+    elseif(CMAKE_SYSTEM_NAME MATCHES "kFreeBSD.*")
+      set(SDL_CMAKE_PLATFORM FREEBSD)
+    elseif(CMAKE_SYSTEM_NAME MATCHES "kNetBSD.*|NetBSD.*")
+      set(SDL_CMAKE_PLATFORM NETBSD)
+    elseif(CMAKE_SYSTEM_NAME MATCHES "kOpenBSD.*|OpenBSD.*")
+      set(SDL_CMAKE_PLATFORM OPENBSD)
+    elseif(CMAKE_SYSTEM_NAME MATCHES ".*GNU.*")
+      set(SDL_CMAKE_PLATFORM GNU)
+    elseif(CMAKE_SYSTEM_NAME MATCHES ".*BSDI.*")
+      set(SDL_CMAKE_PLATFORM BSDI)
+    elseif(CMAKE_SYSTEM_NAME MATCHES "DragonFly.*|FreeBSD")
+      set(SDL_CMAKE_PLATFORM FREEBSD)
+    elseif(CMAKE_SYSTEM_NAME MATCHES "SYSV5.*")
+      set(SDL_CMAKE_PLATFORM SYSV5)
+    elseif(CMAKE_SYSTEM_NAME MATCHES "Solaris.*|SunOS.*")
+      set(SDL_CMAKE_PLATFORM SOLARIS)
+    elseif(CMAKE_SYSTEM_NAME MATCHES "HP-UX.*")
+      set(SDL_CMAKE_PLATFORM HPUX)
+    elseif(CMAKE_SYSTEM_NAME MATCHES "AIX.*")
+      set(SDL_CMAKE_PLATFORM AIX)
+    elseif(CMAKE_SYSTEM_NAME MATCHES "Minix.*")
+      set(SDL_CMAKE_PLATFORM MINIX)
+    endif()
+  elseif(APPLE)
+    if(CMAKE_SYSTEM_NAME MATCHES ".*Darwin.*")
+      set(SDL_CMAKE_PLATFORM DARWIN)
+    elseif(CMAKE_SYSTEM_NAME MATCHES ".*MacOS.*")
+      set(SDL_CMAKE_PLATFORM MACOSX)
+    elseif(CMAKE_SYSTEM_NAME MATCHES ".*tvOS.*")
+      set(SDL_CMAKE_PLATFORM TVOS)
+    elseif(CMAKE_SYSTEM_NAME MATCHES ".*iOS.*")
+      # !!! FIXME: remove the version check when we start requiring >= 3.14.0
+      if(CMAKE_VERSION VERSION_LESS 3.14)
+        set(SDL_CMAKE_PLATFORM IOS)
+      endif()
+    endif()
+  elseif(CMAKE_SYSTEM_NAME MATCHES "BeOS.*")
+    message_error("BeOS support has been removed as of SDL 2.0.2.")
+  elseif(CMAKE_SYSTEM_NAME MATCHES "Haiku.*")
+    set(SDL_CMAKE_PLATFORM HAIKU)
+  elseif(NINTENDO_3DS)
+    set(SDL_CMAKE_PLATFORM N3DS)
+  endif()
+  if(SDL_CMAKE_PLATFORM)
+    set(${SDL_CMAKE_PLATFORM} TRUE)
+  endif()
+endmacro()