My code is actually compiling and running fine, but I am getting 1 warning which I would like to eliminate (I like to see 0 errors and 0 warnings instead of 0 errors and 1 warning )

Here is the code:
Code:
//Defines
#ifndef sqr(x)
#define sqr(x)		x*x
#endif
The warning is stated thus:
inc/path.h:32:12: warning: extra tokens at end of #ifndef directive
I assume this has to do with the parser finding some extra tokens after the first line (the #ifndef line), but before the second line (the #define line).

Anyone know what's up here?