--- gimp-2.8.0/plug-ins/twain/tw_func.h.orig	2012-05-05 17:44:23.000000000 +0200
+++ gimp-2.8.0/plug-ins/twain/tw_func.h	2012-05-05 17:44:26.000000000 +0200
@@ -234,8 +234,10 @@
 void setClientData(pTW_SESSION session, void *clientData);
 pTW_SESSION initializeTwain(void);
 
+#ifdef WIN32
 void LogLastWinError(void);
 BOOL InitApplication(HINSTANCE hInstance);
 BOOL InitInstance(HINSTANCE hInstance, int nCmdShow, pTW_SESSION twSession);
+#endif
 
 #endif /* _TW_FUNC_H */
