Index: uspace/lib/c/include/io/verify.h
===================================================================
--- uspace/lib/c/include/io/verify.h	(revision 0fa34dda5c55295515ecd984f5b5364c4e1d0206)
+++ uspace/lib/c/include/io/verify.h	(revision b2fa2d86f31fd2f3a0ce7dad1f5039f5efa891f1)
@@ -38,6 +38,11 @@
 #ifndef NVERIFY_PRINTF
 
+#ifdef __clang__
+#define PRINTF_ATTRIBUTE(start, end) \
+	__attribute__((format(__printf__, start, end)))
+#else
 #define PRINTF_ATTRIBUTE(start, end) \
 	__attribute__((format(gnu_printf, start, end)))
+#endif
 
 #else /* NVERIFY_PRINTF */