How to avoid "warning: #import is obsolete"

[Andreas Hoeschler]

Hi all,

...
 Compiling file FBRelationCarrier.m ...
FBRelationCarrier.m:3:2: warning: #import is obsolete, use an #ifndef 
wrapper in the header file
 Compiling file FBDataExtension.m ...
FBDataExtension.m:3:2: warning: #import is obsolete, use an #ifndef 
wrapper in the header file
 Compiling file FBErrorManager.m ...
FBErrorManager.m:3:2: warning: #import is obsolete, use an #ifndef 
wrapper in the header file
 Compiling file FBStringExtension.m ...
FBStringExtension.m:3:2: warning: #import is obsolete, use an #ifndef 
wrapper in the header file
...

please, how can this be suppressed. I found an article abiut this issue 
mentioning -Wimport. Where do I have to put or delete this string to 
avoid these warnings? Thanks a lot!

Regards,

   Andreas