--- a/source/Irrlicht/COSOperator.cpp
+++ b/source/Irrlicht/COSOperator.cpp
@@ -11,8 +11,8 @@
 #else
 #include <string.h>
 #include <unistd.h>
-#ifndef _IRR_SOLARIS_PLATFORM_
 #include <sys/types.h>
+#ifdef _IRR_OSX_PLATFORM_
 #include <sys/sysctl.h>
 #endif
 #endif