diff --git a/CMakeLists.txt b/CMakeLists.txt
index d0285be0..52e2ee58 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -592,9 +592,6 @@ check_include_file(OpenGL/glu.h HAVE_OPENGL_GLU_H)
 
 # Win32 IO
 set(win32_io FALSE)
-if(WIN32)
-  set(win32_io TRUE)
-endif()
 
 set(USE_WIN32_FILEIO ${win32_io})