1 files changed, 3 insertions, 1 deletions

diff --git a/toxcore/logger.h b/toxcore/logger.h
index 2a6ee2ed..acd21fb8 100644
--- a/toxcore/logger.h
+++ b/toxcore/logger.h
@@ -67,7 +67,9 @@ void logger_callback_log(Logger *log, logger_cb *function, void *context, void *
  * If the logger is NULL, this writes to stderr. This behaviour should not be
  * used in production code, but can be useful for temporarily debugging a
  * function that does not have a logger available. It's essentially
- * fprintf(stderr, ...), but with timestamps and source location.
+ * fprintf(stderr, ...), but with timestamps and source location. Toxcore must
+ * be built with -DUSE_STDERR_LOGGER for this to work. It will cause an
+ * assertion failure otherwise.
  */
 void logger_write(
     const Logger *log, LOGGER_LEVEL level, const char *file, int line, const char *func,