diff --git a/libtiff/tiffio.h b/libtiff/tiffio.h
index 221dfa5a..6274f098 100644
--- a/libtiff/tiffio.h
+++ b/libtiff/tiffio.h
@@ -261,8 +261,10 @@ typedef struct {
 #define LOGLUV_PUBLIC 1
 #endif
 
-#if !defined(__GNUC__) && !defined(__attribute__)
-#  define __attribute__(x) /*nothing*/
+#if defined(__GNUC__) || defined(__attribute__)
+#  define TIFF_ATTRIBUTE(x)    __attribute__(x)
+#else
+#  define TIFF_ATTRIBUTE(x) /*nothing*/
 #endif
 
 #if defined(c_plusplus) || defined(__cplusplus)
@@ -452,10 +454,10 @@ extern TIFF* TIFFClientOpen(const char*, const char*,
 	    TIFFMapFileProc, TIFFUnmapFileProc);
 extern const char* TIFFFileName(TIFF*);
 extern const char* TIFFSetFileName(TIFF*, const char *);
-extern void TIFFError(const char*, const char*, ...) __attribute__((__format__ (__printf__,2,3)));
-extern void TIFFErrorExt(thandle_t, const char*, const char*, ...) __attribute__((__format__ (__printf__,3,4)));
-extern void TIFFWarning(const char*, const char*, ...) __attribute__((__format__ (__printf__,2,3)));
-extern void TIFFWarningExt(thandle_t, const char*, const char*, ...) __attribute__((__format__ (__printf__,3,4)));
+extern void TIFFError(const char*, const char*, ...) TIFF_ATTRIBUTE((__format__ (__printf__,2,3)));
+extern void TIFFErrorExt(thandle_t, const char*, const char*, ...) TIFF_ATTRIBUTE((__format__ (__printf__,3,4)));
+extern void TIFFWarning(const char*, const char*, ...) TIFF_ATTRIBUTE((__format__ (__printf__,2,3)));
+extern void TIFFWarningExt(thandle_t, const char*, const char*, ...) TIFF_ATTRIBUTE((__format__ (__printf__,3,4)));
 extern TIFFErrorHandler TIFFSetErrorHandler(TIFFErrorHandler);
 extern TIFFErrorHandlerExt TIFFSetErrorHandlerExt(TIFFErrorHandlerExt);
 extern TIFFErrorHandler TIFFSetWarningHandler(TIFFErrorHandler);