diff --git a/timemanager/CCSDSTime.cpp b/timemanager/CCSDSTime.cpp
index f99f8fbb..35c0ef55 100644
--- a/timemanager/CCSDSTime.cpp
+++ b/timemanager/CCSDSTime.cpp
@@ -158,7 +158,7 @@ ReturnValue_t CCSDSTime::convertFromASCII(Clock::TimeOfDay_t* to, const uint8_t*
 	}
 // Newlib nano can't parse uint8, see SCNu8 documentation and https://sourceware.org/newlib/README
 // Suggestion: use uint16 all the time. This should work on all systems.
-#ifdef NEWLIB_NANO_NO_C99_IO
+#ifdef NO_C99_IO
 	uint16_t year;
 	uint16_t month;
 	uint16_t day;