diff --git a/lib/common/cmp_debug.h b/lib/common/cmp_debug.h
index a4c18dfbba0eaec324032e0d19f6b4f878ffa115..1261289366ad362aef4052852d75f8a3560d618a 100644
--- a/lib/common/cmp_debug.h
+++ b/lib/common/cmp_debug.h
@@ -41,6 +41,7 @@ void cmp_debug_print_impl(const char *fmt, ...);
 #  define debug_print(...) do {} while (0)
 #endif
 
+__extension__
 #define debug_print_level(level, ...)			\
 	do {						\
 		if (level <= DEBUGLEVEL)		\